Okay, I totally raided my Bookmarks folder...

ASAN (Autistic Self-Advocacy Network)
US disability-rights group specifically focused on autism. (Asperger's counts since it's a subtype.)

The Asperger's Survival Guide
Informative guide written by an AS man about how to navigate the social world.

Aspies For Freedom
Forum for people with various kinds of autism; started out with Asperger's but has a fuller spectrum nowadays. Tends to be fairly militant autism-rights, but generally supportive.

Autreat
Yearly gathering for autistic people; works like a convention.

The Therapy Shoppe
While it's generally kid-focused, you'll find a lot of useful stim toys and other sensory gadgets here.

This Way of Life
Autism advocacy site with a bit of everything. Especially recommended are the sections under "Autistic Differences" and "Help for Autistics". Executive dysfunction, for example, can be quite a troublesome problem, and one not usually addressed by standard therapy.

Autism Information Library and autistics.org
A collection of articles, generally by autistic people, about life with autism, advocacy, their experiences, and more than a few full-on rants. The main autistics.org site also contains some useful resources.

Neurodiversity.com
Another information library. Links to a lot of scientific stuff, and a lot of explanation of the concept of "neurodiversity" (i.e., the concept of a society that includes and accepts people with all sorts of brains, including autism). Very big on debunking the vaccine/autism myth.

Ballastexistenz
Blog by an autistic woman who's considered a leader in the autism rights movement. Tends to write a lot about disability rights, random daily stuff, and cats.