I have bought many OCD books, and found this one the most helpful. As well as being thoroughly informative it also has a large section in order for you to work through your particular obsessions and compulsions with the aid of examples from other ocd'ers. The book is like having your own 24hr personal therapist!
What I found great was that chapter ten is there for others to read, such as family members and loved ones so that they understand what people with OCD go through. It provides them with a plan if they decide to be helpers and the skills to deal with OCD'ers irrational thoughts. My family are far more supportive and helpful now, after reading chapter ten.
If you have OCD, this book will most definately help.