A note of caution about playing with those more advanced than you...know when to stop playing.
I learned more by listening intently with my mandolin on my lap. I expect the same courtesy from new players now that I showed when I didn't know my ass from my elbow.
To thwart any caustic replies, I am all for inexperienced people playing with more experienced people, and as a matter of fact, I try to insert myself in as many "High-Caliber" jams as I can. I think that if the newbie realizes (earlier=better) that they can call a tune at their tempo and most folks will enjoy it, even if it is "Cripple Creek" at 60 bpm, they will not be as nervous and enjoy the experience more. The flip side is, after you called your tune, KNOW WHEN TO PLAY AND WHEN NOT TO PLAY.
Don't be a jam-buster. That's all I ask.