I'm rather proud of myself. Took the guitar to the session last night and actually played it. Folks were very helpful. The main guitarist knew I was watching his hands and looked at me encouragingly. One guy told me the chords - "It's a G, D, G, F, C, G, etc. OK, got it?" (Yeah, right.) What worked best was using my own ear and watching hands. The hands were a bit of a problem in that other guitarists have more usable fingers than I do, so which fingers they used would confuse me. Had to look at the strings and the patterns, not the fingers. After a while, I started hearing how the chords sounded in general instead of how they sound in a particular song or tune. I already know the tunes, so I could somewhat anticipate what chords were coming.

The best parts about playing with real people are:
1) Getting over nervousness. There's a syndrome, don't know what the name is (shower syndrome, basement syndrome, I-can-play-it-just-fine-at-home syndrome) which is perhaps my number 1 handicap. The ONLY way to get over it is to play outside of those "safe" places.
2) Flexibility/adaptability. Funny how, on recordings, folks play the same music the same exact way every time you hear it. Nobody throws a different tune in the set, it's always at the same speed, the chords are always the same, the breaks come in the same places, and they never switch the key of a song to suit a different singer. 3) Learning to use visual clues. You don't need to know this if you never play with other people, but it's another method of learning. There's sheet music, there's learning by ear, and there's learning by watching. I never used this much playing fiddle, because fiddlers' fingers move too darned fast, but with chorded instruments, it's an incredible learning method!

Although other folks (hi Rick) have told me all this, it takes doing it for the reality to really sink in.

Having one "picking partner" is different from a session, and may be more comfortable. You also get the chance to stop and talk about the music or slow it down to learn it, and you can't usually do those things in a session. You can work out arrangements instead of trying to improvise them on the fly. Luckily for me, I already know these guys and the songs/tunes, and I already play another instrument. For learning purposes, a partner may suit the needs of others more than a session, but they're both great ways to learn how to play well with others.