R C Tonewoods & Sons
I have used R C Tonewoods for exotic tonewoods. I have been very impressed with the user friendliness of their site, the quality of their guitar back and side sets and their excellent and responsive customer service. They always seem to have a large and diverse selection of woods to choose from. If you are looking for great service and great products give these guys a try first.
I have had some lovely wood from Drew at Adirondack, very friendly and helpful with great customer service.
Zootman is R C Tonewoods ebay store.
Guitar Bench Magazine
This is a great resource for information on tonewoods.