This book is highly recommended. As you might expect from John Nunn, the material is excellently selected and instructively written. Basically, it is a checkmate puzzle book with exercises ranging from the elementary to the extremely challenging. I can't help feeling that anyone working through this book will improve their chess game.
But the main reason for writing my first ever Amazon review is to explain how brilliantly the book is rendered on the Kindle. If you've read chess puzzle books before you will know that it can be a real pain to keep switching between the puzzle page and the corresponding answer page. In this Kindle version the author has arranged the pagination so that you get a single puzzle on a page, followed by the solution on the following page. As there are over 1000 puzzles, this wouldn't really be possible in a paper publication but it works excellently on the Kindle. The diagrams are very clear so it is all easy on the eye.
I do hope that the author publishes his other books on the Kindle.