Windows Phone 7 XNA Cookbook

If you’re a programer looking to get into Windows phone 7 game development, this is a great place to start. The book includes pretty much all the basic information you need to interface with the phone for developing a game. This includes setting up the tools, interacting with touch and sensors, 2d and 3d rendering, collision detection, audio, and launching onto the marketplace.

Although this game will teach you the tools to be able to develop a game, it does not actually go through creating a complete game.

So I would recommend this book to someone that has C#, or general programming experience, and has either made a few games before, or can look at the table of contents and see how they can use the tools taught in the book, to create their own game.
You can pick up the book here:
http://www.packtpub.com/windows-phone-7-xna-game-cookbook/book