If you want to learn what a classically trained Southern Appalachian fiddler CAN sound like, listen to Rayna Gellert. Totally amazing, but I expect people as talented are few and far between.
Brad Leftwich has a couple of excellent Old Time fiddle instruction videos - well worth the money, and will answer many questions.
Cheers
Ray (who didn't start fiddling till he was 57 and sounds like it)