Bluegrass
Cybergrass - The Original Internet Bluegrass Music Magazine, providing bluegrass music promotion for over 9 years.
Bluegrass World - features artists, festivals, record companiaes, catalogs, radio stations and numerous useful links.
Fiddle-Related
Fiddler Magazine - an informative, educational, and entertaining resource for fiddlers, accompanists, and appreciative listeners.
Old-Time
Old-Time Music Home Page - David Lynch's excellent site with events, OT musician directory, fiddler's hall of fame, links, LOTS more. Highly recommended.
Jam Session Etiquette
Dulcimetiquette - (jam session etiquette according to me) by Paul Goelz. Especially for dulcimer players.
Jam Etiquette - Ernie Hill. This is from the newsletter of the Walnut Valley Festival: "Walnut Valley Occasional", Volume 24, Number 2.
Instrumental Instruction
Mandolin - A Beginning Bluegrass Lesson - From the Mandolin Cafe. Check out the other lessons. too.
ezFolk Richard Hefner's instructional site for banjo, ukulele, guitar, and harmonica, with lots of TAB and tutorials.
AndPlay.com Banjo - Learn to Play or advance your skills with Instructional Music Videos
Jams
folkjam.org - Listing of jam sessions, festivals and workshops