Resources for developers new to the Mac platform:
- Depending on what you're touching, you may not need to modify UI code or write Objective C at all in which case you don't really need any of this.
- Cocoa Programming for Mac OS X by Aaron Hillegass is a great starter book on Cocoa programming, working through the examples will get you pretty far in terms of understanding the fundamentals of Cocoa.
- From C++ to Objective-C by Pierre Chatelier is a free online book introducing Objective C.
More in-depth stuff:
Stuff you should read on this site: