Great book, although it assumes some prior knowledge, it easy to understand even for a novice at Photoshop like me. I used to be a complete Dummy at Photoshop, but after several hours with this book while at my computer, I have gone a little way into areas of Photoshop that I once thought were beyond me. The exercise sections are really good, and give you a nice warm feeling inside when you have successfully completed them. I have achieved a lot with the help of this book, and am now producing, what I think is above average Photoshop work.
I have a fairly dated Photoshop 7, and now wish I could afford a later version, but sadly my pension will not run to the vast sum of money that Adobe are asking for CS5.