If you're used to programming in the MS world, you're in for quite a shock. It's a pretty steep curve for most (me included.) Here's my suggestion: Read all the Apple Docs, go through the sample code, pick it apart, break it, put it back together. It'll still make no sense to you. Finally, it'll start to make a little sense to you -- THEN you get to start discovering the bugs in the SDK and the OS. Enjoy!