If your divorce is a "simple" one, then this book may be all you need to do your own divorce. However, it all depends on how acrimonious things are between you and your former partner. If child custody is involved, or there is a mortgage or property to divide, then I reckon you'll need professional legal advice, but this book will still be a useful money-saving tool in your armoury.
I did my own divorce by using this book, and it definitely saved £-thousands for my ex and I in what would have been pointless legal fees, though by the time proceedings began, my ex and I were past the throwing-things-and-yelling stage, and were being reasonably civil.
The book dealt with everything, and made the process a whole lot easier to do and cope with. In fact, by using it I was much more clued-up about the process than my ex, which put me in control of it all (that's a much better place to be in a divorce). I recommend you read the whole book, make lots of notes, and mark all the key pages with post-it notes before you start the divorce process. Even if you don't do your own divorce, it is a useful book to have around, especially if most people around you have "taken sides" and seem to have skewed ideas about what divorce is and isn't.