The most highly recommended books are by Kevin Behan. Others have some value for most dog owners and dog trainers, particularly How to Housebreak Your Dog in 7 Days (ignore everything the author says about dominance, which is old hat). I also recommend the two books on canine body language by Turid Rugaas and Brenda Aloff, with the caveat that these signals are not intentional but unconscious expressions of emotion.
I also really like Emergence by Steven Johnson even though it has nothing to do with dogs. It's an easy introduction to the science of emergent systems, which may explain why a wolf pack is not top-down hierarchy, but a self-emergent heterarchy.