Bandler's Books have already been mentioned, so I'll just remind you about him. There's a lot of useful stuff out there, but then again there's a lot of rubbish, a whole lot of surfers keeping to the wakes of creative geniuses like Richard Bandler.
I recommend you pick up the book "Monsters and magical sticks: There's no such thing as hypnosis?"
This is strictly not NLP, but it involves a lot of the techniques and ideas that lies as a foundation for NLP, so I warmly recommend it.
You'll find it on Amazon,
Bandler's book "a guide to Trance-formations" is also very very good.
Ross Jeffries studied under Kenrick Cleveland, as far as I know, then under his old name Paul Ross. If you stumble across some of Clevelands old tapes you'll hear a guy talking called Paul, who also mentions his alter ego "Ross Jeffries" and how the way he is using the material is helping "thousands of guys" or something.
So if you can find it, Kenrick Cleveland's material has a very straight forward and factual approach to teaching.