I'm afraid I haven't read this whole thread, so please excuse me if I'm saying things that have already been said.

I found that reading books of different trainers is very helpful to educate yourself. You can read what they have to say, discover all their different idea's. AND grab some books about wolves! Their behaviour is very interesting and lots of it are seen between our dogs too. But remember; there are differences...
I saw Fisher already mentioned here. I recommend him a lot! Also; try Stanely Coren! It's very interesting as well.
I recommend reading the books of Jan Fennell most of all. I found her idea's very intriguing.
The advantage of reading books of different trainers, is that you'll get familiar with many different thoughts and idea's. It's the challenge to form your own opinion after reading it all... What method felt good? What methods DIDN't you approve of? And why?
Try a method that appeals to you and feels good, but if you do, really go for it and don't stop halfway. Does it work? How does the dog respond, and is that the way you had thought it would respond?
Does the method work, or does it fail? Can you say why?
Becoming an experienced trainer will mean practise. And of course, sometimes, you WILL fail. It's all part of the learning curve... and even though it's hard... it's the only way.
If you manage to get your hands on an old book on dog training, you'll find it to be completely different from the latest insights. Things changed a lot in quite a short period of time. About fifty years ago, dogtraining was based on a pat on the head if the dog was good, and a kick under his tail if he was bad. (Forgive my very blunt expressing...)
We have learned so much more about dogs now, and there are still lots of things to learn!!