First off you need an idea. Something like "How about a game where you put four Xbox gamepads on a table and the aim of the game is to press a button on the one that is vibrating. A kind of cross between eating jelly and playing Whack a Mole".
Then you need a PC with XNA Game Studio 2.0 on it, the four gamepads and a bowl of jelly (optional). If you want to run the games on an Xbox 360 you must have an active Xbox LIVE subscription and also need to be a member of the XNA Creators Club.
You can find out more about getting started with XNA here.
Then you need a book to learn how to program. I suggest this one. You can find links to Amazon to buy copies on the left hand side of this very page.
Last updated on January 15, 2008 by Rob