If you are just beginning I suggest using one of the 2 popular game development toolkits, PocketFrog or GapiDraw. In my opinion PF has more functionality & is easier to use while GapiDraw is more organised & has wider platform support. Suit yourself as they will both help you create fast games.
As well as this site which is PPC specific you should visit www.gamedev.net which is one of the best dev sites out on the web.
Happy coding
