Here's a link to 57 short radio broadcasts from the '70s and '80s by renowned fingerstyle guitar player/teacher Stefan Grossman, available for free legal download (.mp3) or streaming (.mp3 or RealAudio) from his own site.

There are 4 complete series of broadcasts:
Country Blues Guitar - a 17-part series.
Contemporary Fingerpicking Guitar - a 17-part series.
Fingerpicking Guitar Workshop - a 13-part series.
Styles & Techniques of Country Blues Guitar - a 10-part series.

Each recording is just under 15 minutes in length and they all make fascinating listening.

http://guitarvideos.com/radio/00radio.htm