This book is must-read for anyone interested in dog behaviour! Great for dipping into for quick advice, but also an interesting read from start to finish. Based on positive reinforcement, the techniques shown in this book focus on understanding your dog's behaviour, and replacing the unwanted behaviours with more appropriate ones.
I have a generally friendly Chihuahua, but he occasionally finds larger dogs overwhelming. Slowly, with the help of the techniques details here, he is learning that he can just walk away instead of resorting to aggression.
I would recommend this to anyone with a reactive dog, or those just interested in understanding problem behaviours better.