I second the recommendation of Dan Levenson - if possible, go to the weekend camp that he has at his home in So. Ohio.   It is really important to develop an attack that works for you. I like the David Holt stuff too - that's where I learned to drag my following fingers after the note to get that old-time clucking sound (sort of an upside-down Travis mute).
Also, I think it is more important to learn the syncopated rhythm of old-time music by playing along with chords or single note runs, than it is - at first - to learn a bunch of songs.
Clawhammer is fun in that it sounds better solo than bluegrass - IMHO. But it is also really great to jam with folks who know how to play. The biggest problem I have with jamming is to know if the folks are playing crooked tunes. I know fiddle players love those crooked numbers, so I just try to play quieter once I recognize what is going on. You can also play along with the Funky Seagull cd's for pc's and listen to old timey tunes on Honking Duck to learn the tunes.
Would that I had the time to do all this on a regular basis --- someday........
Chris