Rob Miles has finished his book on XNA development and it will be out in the wild soon. Although we don't have XNA support for mobile devices it is a cool framework which allows you to build games for both PC and XBox 360 with managed code. You can see a couple of sample chapters from the book which will help you get started with XNA Game Studio from Rob's site Very Silly Games which showcases some of the interesting things you can do with the framework. Not to mention the great puns in the Silly Ideas list.
Read the complete post at http://feeds.feedburner.com/~r/PeterFoot/~3/227474631/GreatXNABookComingSoon.aspx