Some websites with lessons:
Eric Lugosch Fingerstyle Academy has a number of different songs. For most there's both tab and MP3.
The Acoustic Guitar Workshop; range of resources.
Jack Baker's site for New York School of Fretted Instruments has beginner and intermediate tunes, advanced tunes, and some Chet Atkins/Jerry Reed/Merle Travis arrangements. You need Tab/Edit to download the files.
The Acoustic Fingerstyle Guitar page has many arrangements -- also TabEdit, mp3s, etc.
Arrangements from UK guitarist Steve McWilliams including traditional, blues, 20s pop, Celtic, etc., and a beginner's section
Some other arrangements from the late Marcel Dadi and other well-known guitarists, such as Ton Van Bergeyk, Duck Baker, Eric Schoenberg, the late Dick Fegy.