This is an amazingly thorough introduction to autism spectrum disorders. In fact, it may just answer your questions on its own! Covering not just symptoms and diagnosis, but coping techniques and alternative means of treatment, this is the page to check out if you only want to visit one.

Very complete primer on ASD. If you have a question, it is almost surely here! Large article, but each paragraph is important. Highly Recommended!

This site shows others the different kinds of autism. PDD_NOS is what my son was diagnosed with as he has symptoms but not enough to qualify as Asperger's or other specific types.

Incredible article that covers all aspects of Autism. From possible causes, symptoms, and testing. It also talks about possible other health problems that may go along with it. Goes from infancy through adults.

An extremely comprehensive article on autism spectrum disorders. This article covers everything from types, diagnosing, treating, coping to living with and so much more. The article is long, but it will answer most if not all of the questions you may have on ASD.