All of these books have helped me:

Aquarium Corals by Eric H. Borneman


The New Marine Aquarium by Michael S. Paletta


Clown Fishes by Joyce Wilkerson


Giant Clams by Daniel Knop


Pocket Guide To Marine Fishes by Scott W. Michael


Reef Invertebrates by Anthony Calfo and Robert Fenner


Live Sand Secrets by Bob Goemans, Ph. D.