There are many good features of this book, but it could have been better.
On the inside flap, it says the book "... is for every kind of photographer ... written so you can understand the techniques whatever your skill level ... leads you step-by-step all the way ..."
Virtually all the usual procedures are covered. There are photos on almost every page, mostly in full-colour. This is good, but sometimes there may be too many, and it is not always clear which one the writer is referring to. In some cases, I would have preferred the original version to the "improvement". I found numerous explanations less clear than they could be. And there are some actual mistakes. In "Working with Masks", for example, which applies a more interesting sky to a landscape with a lake in the foreground, the (invisible) horizon is incorrectly located, so that the reflection of the sky in the lake is too low down. These are quibbles, certainly but they detract from what is nearly an excellent book, well conceived but not so well implemented.
To summarize: a nice book, but not one to depend on for learning how to use Photoshop.