This book is divided into three parts. The first part discusses basic concepts of Windows Phone 7 programming using example programs that target both Silverlight and the XNA framework. It is likely that many Windows Phone 7 developers will choose either one platform or the other, but I think it’s important for all developers who have at least a little knowledge of the alternative to their chosen path.
The second part of this book focuses entirely on Silverlight, and the third part on XNA 2D. For your convenience, the chapters in each part build upon previous knowledge in a progressive tutorial narrative, and hence are intended to be read sequentially.