Another couple links: first is this fantastic article in the New York Times Magazine (!) about Sunn O))) and avant-metal. Centered around some illuminating interviews with both members of the band, this is a respectful, even admiring article about some of the most out-there metal going on today.
Second is Bagatellen’s I Hate Music forum, which is generally populated by the sorts of people who like seriously avant-garde music but also dig indie rock (and, more rarely, prog-rock). This is a great forum on which I’ve been lurking for the past few months and learning a lot about a shit-ton of artists I’ve never heard of before. If you’ve more or less tapped out the knowledge base of, say, ProgressiveEars (or if, like me, your tastes have shifted away from the sorts of stuff regularly discussed there), I Hate Music might be the next stop.
(This is not to be confused with this “I Hate Music,” which is amusing but hardly edifying.)