Pretty much the best book I've read in terms of helping writers learn the actual mechanics of hunting down and fixing the little horrors that creep into our writing. Once I finished the book I immediately picked up Chapter 1 of my story and went through it utilizing the knowledge I had gained. It was quite amazing how much my ability to see problems with my writing improved.
In terms of how the book presents material, it's quite straight forward. They generally provide an excerpt from a well-known novel, or from a submission to their writing seminars. The piece is chosen because it clearly shows the topic which they are covering in that chapter. They go through and analyze the piece and then present an edited version to show how the writing could be improved. They have several examples per chapter and then at the end of the chapter they have exercises that you can do to practice what you've learned. Answers (or at least possible answers) are provided in the back of the book.