This is a one awesome blog by Joshua Newnham. Just check it out, youll find a lot of nice articles about programming iPhone stuff and much more.

You can buy this book on amazon:

http://www.amazon.co.uk/Cocoa-Programming-Mac-OS-X/dp/0321503619/

Amazon.co.uk Review
Suitable for anyone with a little C++ programming experience who wants to create software for the newest Mac platform, Cocoa Programming for Max OS X provides a slickly packaged and approachable tutorial that will get you started creating state-of-the-art Mac programs.

Book Description
Starting with an overview of the technology, how to approach the device, the authors lead us straight into the heart of iPhone development. As you progress, you'll learn more about various layout engines and view managers, as well as the more meaty topics like accelerometer and GPS APIs. This book is a must-have for anyone interested in getting started quickly and efficiently with iPhone development!

You can buy this book on amazon:

http://www.amazon.co.uk/gp/product/product-description/1430216263/