Title: Cocoa and Objective-C: Up and Running: Foundations of Mac, iPhone, and iPad Programming, Author: Scott Stevenson
Title: Effective Objective-C 2.0: 52 Specific Ways to Improve Your iOS and OS X Programs, Author: Matt Galloway
Title: iPhone Game Development: Developing 2D & 3D games in Objective-C, Author: Paul Zirkle
Title: iPhone Open Application Development: Write Native Objective-C Applications for the iPhone, Author: Jonathan Zdziarski
Title: Learn Objective-C for Java Developers, Author: James Bucanek
Title: Learn Objective-C on the Mac, Author: Scott Knaster
Title: Objective-C for Absolute Beginners: iPhone, iPad and Mac Programming Made Easy, Author: Gary Bennett
Title: Objective-C for Absolute Beginners: iPhone, iPad and Mac Programming Made Easy, Author: Gary Bennett
Title: Objective-C for iPhone Developers, A Beginner's Guide, Author: James A. Brannan
Title: Objective-C Phrasebook, Author: David Chisnall
Explore Series
Title: Objective-C Programming: The Big Nerd Ranch Guide, Author: Aaron Hillegass
Title: Programming in Objective-C, Author: Stephen Kochan