Programming in Objective-C 2.0 (2nd Edition)
"This book spends half the time talking about the Objective-C language itself and half the time talking about Apple's Foundation and Cocoa frameworks. The chapters are well organized and concepts are well explained, so you end up with a solid foundation in the language. It's an easy read even with very little programming experience. The book doesn't cover Cocoa or the other higher level frameworks, but you'll be completely ready to pick it up by the time you're done with this book."