Here's a cool rundown of all-things-folk music:
Folk Festivals, Artists, Instruments, Folk Music
It mentions top folk artists, instruments, festivals and folk organizations. It has some good info.
For instance this list of Folk Podcasts and Online Streaming:
All the Traditions
Bucktown Folk Music Podcast
Folkalley
FolkCast
Folkways
The Folk Music Hour
The Folk Show
Invisible Folk Club Podcasts
Jim Moran's Folk Music Podcast
The Mike Harding Folk Show