BeerAdvocate - Respect Beer.
One of my favourite beer sites to date, and I'm fairly certain their forums can answer brewing questions as well. Also, sort-of not relevant to the topic at hand, but check out www.untappd.com
. It's a fun website that keeps track of the beers you've drank, including homebrews and you can unlocked badges and stuff. I'm on it as "scoobaroo"