Small but useful book on WPF, it' very example driven and it's probably best used as a second book on the subject. The example applications are quite interesting and a bit more involved then the usual textbook toy example, which is a very good feature but could confuse the total beginner. I would recommend reading first a more introductory and detail oriented book like
Windows Presentation Foundation Unleashed (WPF)
and then use this book to see how the various technique can be tied together.