Agama International and Blue Tegu.com--There is lots of information there to get you started. The November 2002 back issue Reptiles magazine article by Bert Langerwerf. The title is "A tegu for you." You won't find any books on tegus unless you can read German. Tegus get included with monitors, big lizards, etc.
There is nothing wrong with starting small, either. Leopard Geckos, African Fattails and other smaller lizards are fun, responsive. Maybe get a pair and learn how to incubate eggs and sell the babies to your local pet store.
Don't get me wrong, my tegu Rufus is a Great pet. It has never made any attempt to bite me out of anger or feistiness. There are times when cleaning, moving items around in his tank he comes up thinking there is food. One of these days, not if, but when, I get bit I know it will hurt. That doesn't mean I will be eating tegu tail if he does. It will be because of his inquizative nature and my not watching out for him and my fingers.
Keep asking questions. You also have to be willing to listen. Don't ask the question if you are unwilling to hear the answer.
Mike B