I'm just starting myself so I won't be much help but I have a few things to say.
A brazing class would be the place to start, I highly recommend it. However, that's not an option for me right now so I'm doing it all myself.
I have the Talbot manual mentioned above and it is really great but the one thing I feel I really need is to watch or have somebody show me how to properly heat up a joint and pull the filler. I've watched a ton of videos online but nothing has really showed me this in a helpful manner. FYI, don't watch the youtube videos "Bicycle Frame Building" by mchimonas unless you're looking for a "what not to do" video.
Another issue I'm having is that I'm using low fuming bronze for practice and my first frame and nearly everything I find is for silver. Oh well back out to the shop for more practice / trial and error.