Patricia McConnell, Ph.D. is an amazing scientist. She's a researcher, a rancher, a trainer, a speaker, and an amazing writer. You'll love her books The Other End of the Leash: Why We Do What We Do Around Dogs and For the Love of a Dog: Understanding Emotion in You and Your Best Friend. They're easy reads and will give an insight into what's going on inside your dog's mind. Fantastic books, I can't say enough good things about them.
She's also got a terrific blog — you should check out The Other End of the Leash. It's fantastic!