Hi Sally,
Welcome to the forum!
Pointers:
1) Have lots of time.
2) Start with a male cham, so you don't have to deal with reproduction before you have regular husbandry perfected.
3) Buy a captive bred animal over three months old from a reputible dealer so you won't have to struggle with acclimation and worms.
4) A healthy cham drinks a bunch of water. When you build or purchase a cage, consider drainage to be one of the very important aspects of caring for him properly.
5) Either have the time to mist 3-4 times a day for 15-20 minutes each time, or buy/make an automatic misting system.
6) Safe, live plants make for a better environment than silk and plastic plants.
7) Bug variety keeps your cham interested in eating. Roaches, crickets, silkworms, butterworms, superworms, mealworms, waxworms, grasshoppers, moths, mantids, a few others. You might want to start establishing colonies of insects now.
8) UVB lighting is really important. Do your research when selecting your bulb. I like the reptisun 10.0 made by Zoomed. Remember that UVB can't penetrate plastic, so those slimline units with the plastic cover over the bulb are useless.
9) Don't try to save money because you will regret it in the long run.
10) Have lots of money available, because these guys are expensive. Expect to spend $1000 plus in your first 6 months.
11) Find a vet that specializes in exotics, and then call and ask the staff the last time they saw a chameleon. Find the most experienced person in your area. In my town, there are no experienced chameleon vets, and my cham has been suffering because of it.
12) Research, research, and more research. Good places to start:
http://www.chameleonnews.com/
http://www.chameleonsdish.com/
http://www.adcham.com/
http://www.chameleonjournals.com/
Good books to own:
Nature's Hidden Jewels- Petr Necas
Chameleons: Their Care and Breeding- Linda Davison
Thoughts for Food- CiN publication
Understanding Reptile Parisites- Roger Klingenberg
I am sure I am missing some stuff, but there are lots of people on this list with lots of knowledge who will add to it.
Heika