Personally, I'd recommend starting with the oldest, rawest, most archaic-sounding field recordings you can find of rural black folk music. I think it would give one a better understanding of the music and it's history to start like that, and then move forward to more modern sounds. A series of recordings that I really love (and recommend to boredatwork) is the 'Deep River of Song' series on Rounder.

Or maybe I'm just babbling because dwditty used EVERY SINGLE ONE of my planned recommendations, hehehe... Oh, wait. I like Victoria Spivey a lot, too.

---Lepus_Rex