Lets start with the basics of what you are going to need to actually do roleplaying. Before you roll dice and write notes on paper, you need a game and a group of players. There are other things you will need but we will talk about them later.
Parents: The price of gaming books has gone up over the years. Generally the books are sold starting with a core book that includes most of the rules, setting information and everything you need to run the game. These are usually around 50 USD, with additional books required for the Game Master who runs the game. The three books required for running dungeons and dragons ar currently 90.05 on amazon.com, Dice may cost another 8 usd.
Next you are looking to find the people you are going to play with. You will probably start by asking your friends. Since everyone, including you, is new to this don't worry about who is going to be bad or good. The one thing you really should worry about is committing to the schedule. Playing five hours every other week is pretty standard in gaming. You are shooting for four people at the beginning. Three is ok, more becomes difficult and slows the game down. Think of being the game master like juggling, three is a start then it gets harder with each ball you add.
After you have your group set up, your next job is to turn them into gamers. If you do a lot of gaming you will find gamers are very similar to each other. We all seem to have seen certain movies and read particular books. You and your friends don't need to go that far, but you need a basic group understanding of the genre you are playing in. Say you are playing in a fantasy game you need to be able to say " The draw bridge lowers, the evil knight crosses with his spear and shield ready." Everyone should understand what you are talking about. Maybe have everyone watch a couple of movies together so you have a common language to talk about the game. If you are the game master running the game, you really should have a picture in your head for everything you describe, so read up or watch movies.
Note: Not all of your friends are going to like gaming or be good at it. A funny thing about gaming is it takes a few tries until you find the right bunch of people. Some of them you may not even like, but they are the right people to be at the game table. Some people don't work well together, others work so well, the game becomes about just them. Your goal is to have everyone having fun.
Recommended movies and Series
Peter Jackson Lord of the Rings trilogy
A Game of thrones Series
Hawk The Slayer
Monty Python and the Quest for the Holy Grail
Original Dungeon Master's Guide Appendix N
Anderson, Poul: THREE HEARTS AND THREE LIONS; THE HIGH CRUSADE; THE BROKEN SWORD
Bellairs, John: THE FACE IN THE FROST
Burroughs, Edgar Rice: "Pellucidar" series; Mars series; Venus series
Carter, Lin: "World's End" series
de Camp, L. Sprague: LEST DARKNESS FALL; THE FALLIBLE FIEND; et al
de Camp & Pratt: "Harold Shea" series; THE CARNELIAN CUBE
Farmer, P. J.: "The World of the Tiers" series; et al
Fox, Gardner: "Kothar" series; "Kyrik" series; et al
Howard, R. E.: "Conan" series
Lanier, Sterling: HIERO'S JOURNEY
Leiber, Fritz: "Fafhrd & Gray Mouser" series; et al
Lovecraft, H. P.
Merritt, A.: CREEP, SHADOW, CREEP; MOON POOL; DWELLERS IN THE MIRAGE; et al
Moorcock, Michael: STORMBRINGER; STEALER OF SOULS; "Hawkmoon" series (esp. the first three books)
Offutt, Andrew J.: editor of SWORDS AGAINST DARKNESS III
Pratt, Fletcher: BLUE STAR; et al
Saberhagen, Fred: CHANGELING EARTH; et al
St. Clair, Margaret: THE SHADOW PEOPLE; SIGN OF THE LABRYS
Tolkien, J. R. R.: THE HOBBIT; "Ring trilogy"
Vance, Jack: THE EYES OF THE OVERWORLD; THE DYING EARTH; et al
Wellman, Manley Wade
Zelazny, Roger: JACK OF SHADOWS; "Amber" series; et al
The Dungeon Master
If you still don't have a good idea of how the game is played, go back and re read the rules. Don't worry it can be hard. The best way ot learn how to be the Dungeon Master, the guy running everything, is to be a player. Look for a game store or some place that has games. Hang out and ask to watch or play when you see a game being run. Think of being a player as being a student.
Parents: If you are looking to help find a game for your child there are a few resources available. Wizards of the coast, the publisher of D&D, maintains a site that lists stores that run games. Meetup and other find a game sites also exist. Gaming stores sometimes us the term Friendly local gaming store or FLGS to indicate their selling roleplaying games. The rise of Magic the Gathering has created more of these stores, so you may have more available than expected. Check out the store with your child to make sure it is an environment you approve of. You can also check into the Pathfinder Society or RPGA.
Ok if you are running a game, the first thing you are going to need is a story. This is the thing you will have your players do. Most game companies sell books or adventure modules for you to run your players through. These are premade stories that have been tested to be right for the game rules. If you are going to create your own you will need to do a lot more work. If you have a module you bought read it a few times. You will need to know a few key points.
If you buy or create your own story, one key thing you need to know is how you will get your party to do that story. Your friends are playing characters that are hopefully heroes and are willing to fight to help people. Maybe monsters attacking would be enough. Maybe they are more mercenary and to get paid to do anything. Whatever the story is you need a clear idea why the players will risk their lives.
The easiest stories are dungeon crawls, your friends just go in, kill bad guys and take their stuff. If you have a story that has lots of changes you need to know when the players have done this thing I need to make something happen so that the story goes here. Each time your story changes you need to know what starts that change, what happens in the middle and where the players end up.
Those things are like the why and what in a role playing game. The How of gaming is usually where dice are rolled and things kills. This part is why the books have maps and people have miniatures. When you are checking out a ruined castle and have skeletons attack your friends. You may start needing extra things. Miniatures or some kind of tokens to represent where the monsters and players are and a battle map can be used. My cousin just used a map inside a see through plastic sleeve and marked things with dry erase pens. Some game masters just describe everything. You will find certain game are meant to be played a particular way. Dungeons and dragons plays best with the battlemat, the game Fate plays best with notes on index cards. If the rules show a bunch of examples with miniatures its going to be best play that way, if not then don't.
Advice from GM Dirk:
Being a Game Master is the hardest job. Players have it easy. As Game Master, keep your ego out of the game; you will be running every person, thing and creature in that universe except for the player-characters. If you do this well you will LOSE all the major fights with the players--but don't worry, because that's supposed to happen. If you do it really well, you will ALMOST kill the players, so they feel engaged and as if they've accomplished something, and they'll be entertained at the same time. It's hard--much harder than just being a player, and if done well it can be a serious gift to your players.
Engaging in these games, it's good to know what the group wants. Some groups may want simple hack-and-slash stories (fun, and easier to manage), while others may want to develop their characters' personalities (harder, and potentially risky emotionally. More trust is required between Game Master and player). A good GM will try to tailor the game to meet players' goals.
A good player will know the rules nearly as well as the GM. This makes play moves long better. The players should also be flexible and allow the GM to apply the rules as needed without too much argument--the GM needs this kind of cooperation to coordinate the game and keep it going. Player or GM, remember that the ultimate goal is to have fun. Players should help the GM have as much fun as they do. Try new things in-game. If they enhance the experience, keep doing them. If not, don't feel like you need to keep doing them, even if stopping requires a big change.
NOTE: If you are beginning and can't buy tons of miniature figures you have a couple of options. Pathfinder sells monster pawns which are little cardboard tokens. Otherwise get tons of dice, different colors are best so you can say red 1 is a troll, green 2 is a goblin. You should buy a battle mat we all have one. Wrapping paper with the one inch squares on the back also works, they are great if you will use the map again and again.
Before you start playing you need to make sure everyone has a character. The character is who they are playing. This means both the idea and name of the character and all the rules. Every game has something called a character sheet you can download off the internet. It keeps all the rules for your character, print one for each player. The game will have rules for making characters follow each step with your players. Usually they will either roll dice to create attribute numbers or have a point system where you make your character. Points are more fair but less fun. Points let you make a character like you want and are good if you already have an idea, if your player does not know, dice are good.
Next your players will pick what they want their character to be and do. Many games of classes, which are sort of like jobs, the character picks from. Other games just have skills but either way you are making a character that does a job within the group. A warrior class is tough; they kill monsters with a weapons. If the character has stealth skills they are going to be scouting and spying. Next you have a race to pick in most games. This usually is just flavoring on top of your class. Maybe you are a dwarf or elf, there are usually special things each can do.
NOTE: You will want to let your friends play whatever they want. This is not always good. If one makes a fighting thief who can't steal or pick locks they have made a fighter or even a bad fighter. The group still may need a rogue to pick locks. Groups need character that cover jobs like healing and tank. The game master has it easier working with a balance group. You the dungeon master may have to rework purchased modules to make them work well with your party; if you let everyone play what they want. You have played WarCraft I'm guessing, a raid without a healer doesnt work well right?
Filling out as much information on the character sheet as you can. The sheet is made to make playing easier. After playing tons people noticed certain things were needed again and again. They put those things on the Character sheet. I usually screw up equipment and spells. take your time and write down everything the character needs along with weight. Make sure they are not carrying 100 pounds of junk. Have them explain anything weird and special they want. Don't be too hard on them at first though. New players may not understand ideas like spell components. Dont kill them off because they don't have water and food. Those are things the characters would realize and go back home for. This is new to everyone be cool.
Before you sit down and play make sure you are really ready. You need some place large enough for everyone to sit comfortable and get up as needed. People often need to stand to demonstrate what their character is doing. You need a table; they keep everyone focused. Have snacks and drinks at least the first time you play. Going to get food can be a fun but the first time you just want to play. Games often get loud, you need a place ok with shouting. Example : My friends played in my parents garage when i was in high school, it was good we could cuss and do whatever, it just sucked in the winter.
Players should have a pencil, scratch paper and their character sheet at least. Really they should have dice, a notebook, the game rulebook, pencils and their character sheet. Diabetics should have insulin and diet soda. Vegan's should bring their own food and all the above
When everyone gets there expect they are going to talk for a half hour. This is dead time you shouldn't be to upset about losing. When you are ready let them know. As the game master you are telling the players everything their characters see, taste and hear. Start with a description of whatever is happening. Even if your group has played many times describing what is happening is a good start. Your players need to know where their characters are in the scene. Once you have that you can start talking about action.
Once you start having events happen you are probably going to start asking the players how their characters react. This usually requires players to start rolling dice. I say players, you may have seen Harmonquest where the game master rolls all the dice. With the exception of rolls to notice things have the players make their own rolls. They like it and it puts knowing the game rules on them. When you get down to combat the more people who understand the rules the better. They sort of run themselves and they can help others.
Before you have your group fight something, you will probably have them wandering around the woods or a castle or something. This part usually has character rolling their skills to notice or do something. You the dungeon master will say "make a perception check" a bunch. How the players do this is determined by the game. You are asking them to see if they notice something, which is determined by their roll. If they succeed or not you tell them something new about what is happening. Bad guys could be sneaking up on the characters, a good role will tell the players they are there. Most of the game, that is not fighting, it talking and rolling skill checks. Don't be worried if your game is mainly those two things.
Roleplaying games break into combat, most rules are devoted to fighting, so it's expected. Most of these games are miniatures games, with a few skill rules. Your games rules should cover everything you need. As the game master your job is to keep the rules flowing. You will be moving the bad guys, determining their actions or reactions and also deciding rules. With the rule just do your best to be consistent and tend to say yes more than no, but If things are actually impossible say no.
I don't want to right much about combat. There are lots of tools game companies have made to help you out. There are whole books that are devoted to helping you here. Listen up you primitive Screwheads is a good one. My point is lots of work has been done and i don't want to get into rules, you have a book full of rules. Online forums can help if you have any questions. There are come general concepts used across most games.
The first gaming term you need to learn is "Round". It is the same thing as a turn in normal board games. If there is a difference it's that the order players go in can change from round to round. A round ends after everyone "goes", including all the bad guys. One of the dungeon masters job is to keep track of this and make sure players go through the round quickly. Don't allow them to do too much as you are usually talking about 10 seconds of action. The game will probably have lots of rules covering what you can and can't do in a round so don't worry. Example : GM Dirk built a pretty cool wood box with blocks he uses to track who goes when on rounds. GM Steve just writes in dry erase on a plastic binder sleeve.
How a player hits is usually not much different than any other skill roll. Damaging bad guys is usually where things become weird. You usually have special rules here along with different dice. If you are playing D&D you are lucky because you are just rolling dice to get a number of damage. That number is subtracted from a total and when you are at zero the player or bad guy are out. Things get harder in other games.
Your game will have lots of rules for all this, you need to know them. You need to know character heal up from a fight. These are the most complicated and least fun rules in games. Sometime they will say character need to go to the hospital for a week and have a month on crutches. Hopefully you are playing a game with healing magic that lets your players fill their health bar just like world of warcraft. One thing you can do is not focus on that part. Imagine sitting in Warcraft with no food to recover, I bet that is boring and slow. It is the same in pen and paper games. The good thing is the game master can just skip that part.
Withdrawing is another new idea. It's running away, but in a way that the rules let you not get beat up while doing it. The idea is you are backing away from the fight weapons out and poking at the bad guy to keep them away. This is hard because you can be totally stuck by the rules. Example : My friends were fighting willow wisps that were killing us, we could withdraw per the rules but they were faster than us so could just advance and attack us again. Since they floated and we were outside on an island their was no way we could escape. We had to fight to the end.
When you friends finally kill a monster or even complete the story you created you are going to be rewarding them. This usually means loot and experience points. There are other things like titles or story rewards like land. But, Loot and Experience are the real things players care about. Giving out money is easy. Magic items are a bit harder as they often alter the game rules. Giving out experience is tricky.
If there are premade magic items in the adventure module stick with those for a bit. Altering what you give can cause problems at the beginning. You don't always know what is right and will give too much or too little. Monty Hall is what we call those that give too much, new Game Masters usually give out far too much. You give Excalibur to a new player they kill everything and fly through levels. Its sort of like being a twinked out character in an MMORPG. Minny Hall it less bad until you hit the point where players basic needs are not covered. If your party can't get a room or eat the players start to complain. There is also a resurrection spiral, you need to avoid. Its where players lost a fight and someone dies, they sell off gear to get them resurrected, then they attempt the fight again because it is part of the story. They loses because they are less without their gear, more die..etc...repeat..until total party kill!
Experience is hard. You want to reward them but not too much. I would say good play should be rewarded with a tangible award every 3 ot 4 sessions and bad play every 6 to 7. What this means depends on the game, a skill award is a pretty small thing so could be less a full level in D&D is big. Also as you continue to play these rewards will eventually increase in cost. Your WOW character levels were easy in the beginning and took most as you leveled right? You need to award enough that players are engaged but not some much that they find it undeserved. Example : My friend Anthony hated WOW because levels came so fast compared to Everquest. In the beginning with new players its sort of fine to over award, but long time players will start to desire a challenge. GM Joseph is all about players scrimping for each resource, even a horse and cart, that is his fun zone.