The Autism Treatment Guide by Elizabeth Gerlach comes highly recommended. Here's a review on amazon.com:

I cannot get over the fact that one woman took it upon herself to gather together in this small, yet totally thorough guide, all the treatments concerning autism available to us here in the United States. This is a remarkable feat.
This Guide is an invaluable asset and you are behooved to own it, if you have an autistic child or adult in your life. It should be in the library of every single person who has any sort of connection to autism, be it professional, or familial. It will show you all the options we can turn to in the most easily understandable manner. It is not a judgemental tract. That is not the intention. It is a source of information and explanations.

Have you read it?