I recently read "The Other End of the Leash" by Patricia McConnell. The author is an animal behaviourist, a dog trainer and has a sheep farm with four working dogs. This book does not tell you how to train your dog, but to help you understand your relationship with your dog. She discusses the differences between how primates and canids communicate. McConnell does stress (which some people forget) that dogs are not wolves just as humans are not chimpanzees. There are similarities but the differences are also important.
McConnell begins by telling us that "All dogs are brilliant at perceiving the slightest movement that we make, and they assume each tiny movement has meaning" We have to learn that we are sending these sometimes conflicting signals and help our dog learn by being consistent with our body language.
When people talk we want to face each other. If we want our dog to come we face him and say "come". Dogs, being great at reading body language, want to go in the direction our feet are pointing. So facing a dog means "stop." Turning your body and telling your to dog to come can be more successful. This was a mistake she made when she was learning how to train her dogs to herd sheep. They were following her feet direction not her face. Once she changed her feet position the dogs did what she wanted to do. Before they were doing what they thought she wanted.
I highly recommend this book to anyone who has a dog or is thinking about getting one.