I have gone to a John Lyons clinic. I REALLY liked him as a person and as a trainer. He is very simple and direct and faith based (might be why I liked him as a person so much). I have gotten a TON of info from his magazine and I recently bought a book that is very good too. Communicating with cues: The reader's guide to training and problem solving part 1. It was $14 and is PACKED with info!
I also check out youtube ALOT! There are tons of people puting up videos of either the actual trainer or themselves following a certain trainer's program. You can learn alot there too. I like the 7 games by parelli. All except the yo-yo game. I like cues though. Its really a matter of what YOU like so that you will stick with it.
Anywho... this is what I do.