The Stanford University course for iPhone Application Development (CS 193P) is a really great course and one all new iOS developers should check out.
This is the official companion text for the popular iTunes U series from Stanford University taught by Paul Hegarty in Fall 2011. The book is full of code examples and animated walkthroughs designed to teach experienced programmers how to write iPad and iPhone applications.
The book is available from the Apple iBookstore. The only downside of this book is that it’s only available in the iBookstore from what I can tell. Which means, I have to read it on my iOS device not on my Mac where I might be coding. Come on Apple, get with the program here.