Matee's Schools
Warrior Way - Walled Lake, Michigan
Khaay Muay Sit-Kangmongdorn - Turtle Creek, PA
Muay Thai Trainers
Saekson Jinjira - Dallas, TX. Muay Thai champion, trainer of Pete Spratt. Kaensak Sor Ploenchit is currently visiting Saekson in Texas, so if you're lucky you can meet Kaensak ("The Michael Jordan of Muay Thai").
Bunkerd - San Francisco, CA.
Chai Earnsmuth - Lansing, IL. Great facility, offering Muay Thai and a large number of other martial arts (Hapkido, American Kickboxing, JKD and even Capoeira!).
Muay Thai Sites
Choke Muay - Reports from fights in Thailand and around the globe. Fighter database. Active forums.
MMA.tv Forums - Very active Kickboxing forum with many excellent Muay Thai practitioners. Very good "Underground" forum with lots of MMA and NHB talk.
Defend.net Thaiboxing Forum - Less active than MMA.tv, but good discussions occasionally.
Sherdog - More generally a site devoted to NHB fighting, there are some good discussions in the forums.