Here are some of the Books that i found were available in the amazon.com .
The Number of Books / resources are plenty for starting with the Windows Phone 7 .
- Beginning Windows Phone 7 Development (Books for Professionals by Professionals) – by Henry Lee
- Windows Phone 7 Secrets – Paul Thurrott
- Professional Windows Phone 7 Application Development: Building Applications and Games Using Visual Studio, Silverlight, and XNA (Wrox Programmer to Programmer) – Nick Randolph
- Microsoft Silverlight Edition: Programming Windows Phone 7 – Charles Petzold
- Windows Phone 7 Game Development – Adam Dawes
- Microsoft XNA Framework Edition: Programming Windows Phone 7 – Charles Petzold
- Windows Phone 7 Application Development (Developer’s Library) – Corey Schuman
- Learning Windows Phone Programming – Yochay Kiriaty
- Pro Windows Phone 7 Development – Rob Cameron
- XNA Game Studio 4.0 Programming: Developing for Windows Phone 7 and Xbox 360 (Developer’s Library) – Tom Miller
- Windows Phone 7 Unleashed – Daniel Vaughan
- Professional Windows Phone 7 Game Development: Creating Games using XNA Game Studio 4 – Chris G. Williams
- Sams Teach Yourself Windows Phone 7 Application Development in 24 Hours (Sams Teach Yourself — Hours) – Scott Dorman
- Learning XNA 4.0: Game Development for the PC, Xbox 360, and Windows Phone 7 – Aaron Reed
- Windows Phone 7 Developer Guide: Building connected mobile applications with Microsoft Silverlight (Developer Series) – Dominic Betts
- Windows Phone 7 Recipes: A Problem-Solution Approach – Fabio Claudio Ferracchiati
- Windows Phone 7 Made Simple – Jon Westfall
- Windows Phone 7 Development with Microsoft Silverlight Step by Step – Andy Wigley, Peter
- Windows Phone 7 Application Development: 24 Hour Trainer – Brian Faucher
- Pro Windows Touch: Developing Touch Applications for Windows Phone and Windows 7 – Keith Harvey
- Windows Phone 7 for iPhone Developers (Developer’s Library) – Kevin Hoffman
Some of the books are available for pre order too .
With so many interests among the Book authors and the publishers , looks like there is more for the developers to choose the right one to start the development .
Don’t forget there is MSDN too so start with .