WPF is quite different from existing Microsoft based GUI frameworks (Win32, MFC, WTL, Windows Forms). It’s good to have a good background knowledge to be able to leverage the potential of this great new architecture. The following books may help you to get you started.

The first WPF book I bought was Applications = Code + Markup (A Guide to the Microsoft Windows Presentation Foundation) by Charles Petzold (Microsoft Press, ISBN: 0-7356-1957-3). Although this book explains the ideas of WPF rather good it has two major flaws:

1. The biggest mistake of this book is that it doesn’t contain any pictures, which makes it very abstract. It’s a book about Graphical User Interfaces, so you definitely need pictures to explain things.
2. The first half of the book doesn’t use XAML, which makes code samples very verbose. Don’t be fooled by the number of pages. All code is written in the book, so it takes up a lot of space.

After a while I ordered Windows Presentation Foundation Unleased by Adam Nathan. This book also describes the fundamentals of WPF, but it is much more accessible, because it uses XAML from the beginning and uses full color screenshots that show what do code does. If you need a good WPF book, then order Adam’s book. It’s definitely worth it.