Education is important. And knowledge will give you a little more to empower yourself. Treatment, although frustrating at times, does not need to be intimidating.
Ultimately, you will be working with your dog. While learning about behavior modification won't teach you exactly how to treat your dog, will be a great benefit to you as an order in understanding how a given program could work, and why you need to comply with the program for your dog.
Further some trainers, even well meaning experienced trainers (never mind scam artists) only pick up the methods of behavior modification without understanding the context of why they work. There are plenty of books written by experienced trainers who are seen as experts with very little academic training, or understanding about learning principals that are behind the methods.
Some trainers or "behaviorists" focus instead on the actions without fully understanding why the methods have evolved. It is a little like the child's game of telephone. The message eventually gets distorted. This is not a concern for obedience training for the normal dog.
Unfortunately, when trying to affect how an aggressive dog thinks, small misunderstandings can affect a dog greatly. For example one trainer recommends you deal with dogs who are afraid of thunder storms by rewarding them for sitting and staying by your side. This may seem similar to desensitization combined with counter conditioning, and yet this suggestion not only will not get rid of the dog's fear unless the fear was very minor or very new, but could actually cause the dog greater anxiety.
Another trainer recommends long crate stays, claiming it is not a punishment, but a way for the dog to gain insight about his situation. If the dog suffers from learned helplessness and become passive in the process, it can seem like the trick worked. But instead the crate is being used as excessive punishment, and the dog may actually become worse, or develop other behavioral problems.
An expert should understand how the principles of learning can be applied to your dog's specific issues. Understand that it is possible to make a situation worse if these methods are done improperly. That is why relying on an experienced expert is essential. They will be able to outline exercises, a schedule, and consult with you about your dog's progress. Additionally a consultant is an objective expert who can help you with timing problems around corrections and rewards (often the biggest difficulty), and when to change correct your tone, posture, or quickness of praise or rewards. It helps if you understand why these things are important.
Accurate diagnosis is essential. Even though your dog and your neighbor's dog both fight, for example, their problems and their treatments may take on very different forms.