Boot camp should already be on your computer, its a part of the operating system. Go to applications>utilities and it should be in there. After that, you just need a copy of windows (at this point 7 is probably the way to go), and it will be fairly self explanatory. Youll need to make a partition of your hard drive specifically for windows and things you want to run on windows. Since you are planning to use it for games, you will probably want to partition a decent chunk of storage. How much exactly will depend on how big your hard drive is, but like i said, for games youll want to make sure you have a lot.
To the other guy, you specifically said you have never owned a mac. a hackintosh'd pc =/= a mac. So yes, you should shut up.