The Parents' Guide to the 11+
I found it very useful. I needed a starting point for tutoring my son and it really helped to get me focused on what was needed with some useful hints and tips. My only criticism was that the motivational example chart could have been better and they could have done with adding some pages for notes at the back of the book. I also bougth the How to books and I would say that they were a bigger help, but ideally you would use all of them.