I was stuck with a fear aggressive dog, which is hard as is. Then let's add in the fact he's 80lbs of solid muscle and deaf! I needed help, and thankfully, was working at the SF SPCA, where Jean Donaldson was working, and so I purchased her book.
It was a huge help, because up until that point I was lost on what to do, I'd never had a fear aggressive/aggressive dog before, and my deaf boy had been the perfect dog park dog, until he was beat up by two related dogs (and no, they were not pitbulls)- my dog is the pit. He was terrified, and would not fight back, it took several minutes before I broke it up (other owner was totally oblivious). After a trip to the pet er, he was sutured up, and returned to the park a week later. At that point I noticed cautious/fearful behavior, and when a small dog mounted him, he freaked out. Not knowing how to respond, I made his fear worse, by tightening the leash when we approached dogs.
The book gave us HUGE progress! He went from being so scared of any dog he saw, and wanting to kill them a block away, to actually being able to walk past dogs, and/or say a quick hi without a problem. It's taken us a long time, but this book was tremendous help (in fact, more help than our $500 trainer!)