I've read it and am working through the exercises. I've done jumping before but was mostly self taught with a few lessons. That book really takes your horse slowly through learning to jump. I think the method is really good and it tells you what to look for and what you and your horse should be learning.
Also each lesson builds on something you learned before. It also has excersizes donated by guests of the author. I really liked it and it's a definite part of my horse library. You can get a used copy on amazon
for about 8.00