I'm still a beginner and have just been playing a little over a year now. All self taught. One of the great resources are continually thrown around on these forums is Scott Devine and his scottsbasslessons.com stuff. I've been a fan for awhile. Anyways, I just threw down some cash for the first play along series (II V I). I just started it today and I looked up and it had been 3 hours of some really great strides in my playing and understanding. It's a damn well put together resource and I highly recommend it. It was perfect for me since I just started playing with some other musicians for the first time and learning to play and improvise some bass lines over some simple chord progressions is really going to help me. And I already feel like I know the fretboard better after that one session. Lightbulbs are going on everywhere! Big thumbs up!! And thanks Scott if you see this!