Underwater Photography and Marine Creatures of Thailand's Andaman Sea and Burma's Mergui Archipelago.
I find that these links here to be an extremely useful source of info from diving daytrip liveaboards PADI courses, identifying fish/critters but also underwater digital photography/video and equipment reviews.
Santana Diving The diving company for which I work as a PADI instructor and tour manager on Santana Diving's MV Discovery. Follow the link to book a course or a diving trip.
Bubblevision professional underwater video.
The Seaslug forum threads on identification, feeding, locations etc.
Underwater Photography Magazine I read it every month, it's FREE Camera/housing reviews, hints and tips, dive reports, new stuff.
Ken Rockwell has written some very informative articles on equipment and surface technique.
Asia Dive Site have a site dedicated to the dive sites around asia with an expanding infobase for the region.