Here are some links that may be helpful:
Cactus & Succulent Society of America A superb resource for everything about cacti and succulents.
Central Coast Cactus & Succulent Society Here is a nice listing of additional links & resources.
CactiGuide.com An excellent, very active forum and lots of resources about just about all aspect of growing cacti.
CactusLovers.com If you love cacti, Arizona and the southwestern desert, you’re in the right place!
Kara Nursery Quality, well-grown succulent plants at a reasonable and fair price.
Navajo Country Books, movies, music and more …
Wikipedia The free encyclopedia !
Amazon.com Amazing collection of books and actual succulents on succulents.