You're in luck. Apple makes a good IDE called XCODE. You can download it for FREE. You also get Interface builder for free, too. Also, check your install disk. It has developer tools on it including code samples.
Most Apple programming is done in a language called Objective-C. It's like C, but not quite. Very object oriented. In order to get the full power of the Cocoa frameworks, you'll want to learn Objective-C.
In addition, you can become an Apple developer for free and you get access to their devel site and places to ask all kinds of questions. I've been coding in Applescript but am seriously considering taking up Objective-C because you don't have to compromise any of your functionality.
If you are going to be talking to interface level stuff, you need to do it in a native language like Obj-C.