The recent issue of Dirty Linen (#83 - August/Sept. '99) has an article titled "internet radio" (pp44-45) with lots of good information. This article is not available on their website, though.

There was also a recent thread titled WKSU (I think), which had some internet folk music sites listed. (By the way, didn't FM -as in FM radio- originally stand for 'folk music'? Seems like at one time that's where we'd hear it.)