Absolute Write: Forum with lots of posts on all aspects of writing
Reddit: A social Web site with tons of stuf, but here are the subreddits that will interest you
Scribophile: Great place to find writing groups and critiques.
Critique Circle: Another great place for critiques.
Scrivener: The big mac daddy of writerly organization.
Jer's Novel Writer: Scrivener's little brother. I use this in the first draft of my writing.
The IndieView: A great collection of bloggers who review indie books.