When I first started training dogs back in the dark ages, one of the most popular, well known trainers advocated such things as "hanging" dogs (lifting their front feet off the ground and letting them dangle from their choke chain, the de rigueur training collar at that time), and brutal "corrections", yanking the dog off its feet to correct it for pulling. This was the trainer for the Disney movies. Eee gads. One day I found a book by Martha Covington Thorne, who long ago met her beloved dogs at the bridge. Suddenly I felt like I was doing things correctly when I tried to make my dogs happy while working with them. Then came Carol Lea Benjamin, Barbara Woodhouse, Brian Kilcommons, Karen Pryor, and many others. To this day, Carol Lea Benjamin, is, to me, the epitome of a dog trainer. More about that later.
Modern dog training, for the most part, is all about making your dog happy. There are, of course, still some of the old-time jerk, twist, and tie them in knots type out there, so if you're looking for a trainer, make sure you observe them in action prior to either signing up for a class or placing your pet in their hands.
There are so many methods for training dogs: "NILIF" training, where nothing in life is free, advocates giving no attention or treats without making your dog work for it (sit, stay, come, or whatever). Clicker training (operant conditioning and behavioral modification are other names for this method) uses a clicker to give your dog a marker, a sound that tells your dog "you did that just right!". The click is a promise to your dog. Once your dog knows a behavior, you don't t have to click every time, and can eventually phase the click out completely, but if you click, you have to treat. Teaching how to clicker train would take this whole post, or more. It's elegant, easy (once you know how to do it), and effective. There are "positive only" methods where bad behavior is ignored and good behavior is rewarded. There are pack driven, wear your dog out and he'll be too tired to misbehave methods. There's "natural training" which emulates real life - sometimes you're good, sometimes you're bad, and you're "rewarded" accordingly. This is the style of Carol Lea Benjamin, Brian Kilcommons, Barbara Woodhouse, and other popular trainers. It's a common sense approach which most closely emulates the way we humans interact with each other.
I'm what "pure" clicker trainers would disparagingly call a "cross-over" trainer, or "a trainer with a clicker". I've been training a long time, and I just don't think a single training method best fits every situation. I use all the above methods, other than the old-time, heavy handed approach, depending on the dog and what behavior(s) I'm working on. For Bruce, who needs to learn a specific set of behaviors for an employee training video, I've been doing a lot of clicker work. It's the most expedient method of getting him from point A to point B in this situation. In general, I follow a more natural training approach. The way I see it, in real life, whether you're human, wolf, or dog, there are limits that need to be respected. If I've walked, played with, fed, and watered my dog. Made sure he's had a fulfilling day, and he still insists on sitting in the doorway, chewing the molding, he's going to go into his crate for 15-20 minutes. If he's heading down the bad-dog road, he'll spend some time learning that NILIF. When I want him to learn how to turn on a light, I'll probably teach him to "target", and use a clicker.
The bottom line of all this is that while there is no one right way to train a dog, there's definitely a wrong way. Your dog is your buddy, your pal, your friend. She depends on you for so many things, not the least of which are to keep her safe and fulfilled. Dog's love to have a job, overcome obstacles, and succeed. Learning basic commands is a good way to start. So find a trainer you like and trust. Someone your dog likes as well, although this may take a little time, since good trainer's are, by nature, "alpha", and tend to radiate that in their bearing around dogs. Find someone who is kind, but firm, and hasn't lost their joy in dogs. This may not be easy. You may need to talk to several trainers. If possible, set up a private lesson before you commit yourself to a 6 or 8 week class. It's worth the effort. You'll be happy, your dog will be happy, and soon, with a little work, you'll have your very own socially acceptable dog.