Beginning iOS 4 Application Development
By Wei-Meng Lee

This book has become my go to resource for starting out in iOS development. Unlike other books on the subject the author gives a clear overview of building with the built in tools and then covers building apps programatically. This is very good approach because the student learns how to build apps in more ways that one. The code being printed in color also makes the code very easy to follow and replicates the display in Xcode 4.

Learn Objective-C on the Mac book
By Mark Dalrymple , Scott Knaster