Authors I would recommend.

The authors on the list below represent humane, positive training. ANY of their books I would highly recommend.

Pat Miller, founder of Peaceable Paws Dog and Puppy Training
Karen Pryor, A real pioneer of positive dog training, leaving behind old techniques such as force, punishment and goes on to introduce clicker training to the pet owner
Patricia B. McConnell, Ph. D.
Jean Donaldson
Dr. Ian Dunbar, Ph.D animal behaviorist, veterinarian
Pamela J. Reid Ph. D
Pamela S. Dennison
Brenda Aloff

Other authors that have written great books on dog communication and body work
Linda Tellington-Jones
Turid Rugaas

Great dog books about dogs but not training specific
In Defence of Dogs by John Bradshaw
The Inside of a Dog by Alexandra Horowitz
The Other End of the Leash, by Patricia McConnell
For the Love of a Dog, also by Patricia McConnell

Medical reference books for the layman.
The Dog Owners Home Veterinary Handbook, James M. Giffin MD and Liisa D. Carlson
The First Aid Companion for Dogs and Cats, by Amy D. Shojai

This is by all means NOT a comprehensive list, but a great start if you want to learn about dogs, training and interacting with them in a positive way. Knowing how to read the dogs signs and how they think, see, smell and hear helps you to be a better interpreter and communicator with all dogs, not just your own! Happy reading, Happy training!