IDK of any specific yorkie training books but don't think, if you really want them trained, that yorkies are much different than other breeds, being that you would use the same techniques.
Even though treats may not always be available at later times, when you're beginning to train it is important the dog get a consistent reward for completing the requested task. So, I would continue to make treats (or whatever works) the reward for some time. At some point, you should be able to give a treat one time, then just praise the next time, going back and forth this way. Eventually the treat portion of the exchange should be able to be dropped with just praise given.
__________________  ~Ruby, Reno, Razz, & Jack~ |