The free ebook, Programming Windows Phone 7 by Charlie Petzold, is now available from Microsoft Downloads. This thing is huge: over a thousand pages of WP7 goodness. Despite this, I searched the text on MVVM and ViewModel and I came up empty handed, so there’s likely a lot more you can discover beyond this book. I’d read this one as a starter book, then move on to more advanced Silverlight techniques if you’re writing the type of application that could benefit from them.

If you’re already familiar with WPF/Silverlight, much of the material can be skimmed over. There are likely WP7 specific goodies hidden in the text, but you’ll likely benefit from the chapters dedicated to WP7 specific topics such as Chapter 5: Sensors and Services.

The XNA section is a good overview as well, but if you want a deeper dive check out Professional Windows Phone 7 Game Development by Chris G. Williams and George W. Clingerman.

While searching for that book on Amazon, I found that there is a slew of books coming out in the next few months (even a For Dummies, what?!). Be prepared! I already have my first app written, do you?