I don't remember if I've mentioned it here before, but I run a (smallish) writing community: Bookzek
All kinds of writing are welcome. The site is centered around giving and receiving critiques. There are basic guidelines for those, nothing strict or fancy.
For the most part, though, we just try to be supportive of each other's efforts and sometimes collaborate on things. There are forums, blogs, and that sort of thing available.
We're always looking for new members, so feel free to sign up!