Many of us, myself included, read til 3am every night for weeks before getting our first chameleons. There's SO much to know, and if you read all the articles/issues that interest you over at
www.chameleonnews.com (go to Past Articles for complete list of articles).
TAKE NOTES! is all I can say, there's so much knowledge that it's important to take notes for what you think is important, because you'll forget otherwise
Another great thing to do is set up the enclosure first for one month, measure the temps, figure out how to keep humidity at the desired range, etc.
If you will be breeding your own roaches or other insects, get those started too, buying food from the pet store can get REALLY expensive, and buying in bulk would go to waste with only one chameleon.
Other than that, enjoy! They're the greatest pet lizard in my opinion.
Ask lots of questions.