...surely if you are going to bother including before and after photos you should be able to tell the difference!
As someone who is new to this software and to digital photography manipulation in general, I found this book really helpful. It's a little bit cheesy in parts, especially the foreword to each section, but the core content is good. I certainly learnt a lot from it (and continue to do so). The only real issue is the quality of the photos (which is a shame, given the purpose of the book). Most example photos are next to useless. In one section they show a whole list of thumbnails which are supposed to show the application of different masks. Unfortunately they all look exactly the same.
Notwithstanding the above, the book is a useful reference for the software.