The Pragmatic Programmer

Author: Andrew Hunt and David Thomas

http://www.pragprog.com/titles/tpp/the-pragmatic-programmer

While not a book strictly related to programming on the iPhone or in Cocoa, I thought I'd add it to my list of recommendations based on the general applicability of its contents.  This is a course for professionals, and there are many things to learn to have a great career beyond the nuts and bolts of programming the particular platform you're on.  This book is filled with great lessons that the authors have learned over the course of their time as developers, some of which might seem like common sense, but all of it is valuable.  

If I were designing a modern computer science curriculum, I would require that you read this book before graduation.