Tons of stuff on youtube as well and articles on the net. But a good book by a decent trainer makes a good read. I think I have a Joe Irving book.
I have found that as your trying to train, work a dog and you are a year or two in you can then view,read stuff and you think ah yes that makes sense. I can see now where I went wrong and why and I would have been better doing this and that. You can also spot the complete rubbish.
I guess its called experience