I would highly recommend this book to anyone wishing to pass their theory test! It contains all the possible questions and answers, so it is near on impossible to fail! I literally only spent the day prior to my test going through the booklet and I scored 50/50. I found I didn't need to read through the highway code (which is located at the back of the book) but it's useful to have, I imagine especially if you plan on starting the theory before getting out and about on the road.
This book obviously doesn't give you any experience of the Hazard Perception part of the test - however, you can find many free tests online, which is what I used to practice. So there really is no need to get lured into buying those expensive DVD's! All you need is this book and the internet!