All the books recommended are great books and I would recommend anyone of them.
1. Canine body Language (Photographic Guide) - Brenda Aloff - Indispensable!
2. Bones would rain from the sky - Suzanne Clothier - Wonderful!
3. If you read and liked Culture Clash - Jean Donaldson - Follow up with Dogs are from Neptune (also by Jean) it gets little recognition but is a good book even with all the typos, spelling and grammatical errors. 
And.. On Talking Terms w/dogs; Calming Signals by Turid Rugaas: Simple little book. It's cheap and doesn't look like much, but the content is awesome.
Knowing you are not a novice and based on your ability to get down into the depths of some discussions. I will recommend a couple of books that are not your everyday "train this way" books. I think you might enjoy them as they are based on sciences and studies. They are truly very informative and interesting and will make great additions to your library.
How Dogs Learn by Mary Burch, PhD & Jon Baily. A text-y type book but easy read. It explores operant conditioning and applied behavior modification (where science and dog training meet). The basic principles of behavior and how they can be used to teach your dog new skills, diagnose problems and eliminate unwanted behaviors. Easy read, very affordable.
The Domestic Dog: Its Evolution, Behavior and Interactions with People. Cambridge University Press published this book sometime in the mid 1990's (1996 I think). It's carefully researched on canine behavior and development. For the general reader, the writing style may be a bit dry; however, because each chapter has different authors, the writing style, while basically academic and fact driven, varies. It is an expensive book but being that it is so full of information its worth it (IMO). I learned a lot from it, found it very interesting and love having it in my library.
Dawn