The Chameleon Keeper's Reference Series Volume 1- Care and Breeding of Chameleons. Edited by Philippe de Vosjoli and Gary Ferguson. This book was Copywrighted in 1995, but has some really good sources of information. The book focuses on specifically four major chameleon species. The Panther chameleon, Jackson's chameleon, Parson's chameleon, and Veiled chameleon. It's a fairly good source, and I would recommend starting there.

All About Chameleons and Anoles, by Mervin F. Roberts. This book is DEFINITELY outdated!! It's from 1981, a long time before veiled chameleons were even around as pets. This book I'm only mentioning as something to read for comparison to other sources. It's always good to have more than one source of information on hand, even if it is that outdated.

Reptiles magazine, Guide To Keeping Reptiles and Amphibians. This magazine is great for anything! Specifically, the February 1999 issue has an article all about veiled chameleons. This will help, and is more updated than the previous sources. Their webpage is on www.animalnetwork.com

Other great sources of information:
As always, a breeder is a great person to talk to. Heck, if someone is even able to breed veiled chameleons, then you know they must be doing something right!
Another good source is a pet store that carries them. Ask the employees and manager about them, they may know more than you might think!
One other good source is your vet. You need a vet for the veiled chameleon anyway, so you might as well start asking around. Trust me, it'll be harder than you might think to find a veterinarian who will care for any reptile.

Along my surfing of the web, I have found some excellent sources of information. I'm going to post as many as I find that I believe are the most complete sources of information.
Veiled Chameleon Lizards
The Veiled Chameleon Care Sheet
Veiled, or yemenite chameleon
http://members.tripod.com/~riel/veiled2.html

forums to visit: These are great places to talk to other herp owners, and many experienced people visit these boards as well!

Acmepet.com
Kingsnake.com <~~EXCELLENT place to go!