I've had really good experiences with Community Bike. When I got my first bike (used, neglected, etc), I went there for advice and parts, as I didn't know much at the time. They set me on the right track - Phil spent a half an hour showing me exactly what I needed to do. (Of course, I walked out the door with $200 in parts and tools, but it was worth it.) They seem to cater more to commuters, though, which doesn't sound like what you're looking for.