One of my favorite songs to listen to is rainy day, dream away by jimi hendrix. I love the laid back feel it has and the way the guitar and sax play with each other. Are there any other songs or artists who play that way? I wanted an album full of stuff like that that was mostly just laid back, mostly instrumental jamming.
check out phish and the dead. medeski, martin and wood is good as well, and they're very jazzy. a lot of Yes songs include very lengthy all instrumental parts as well, so you could check them out too. hope that helps.
+ really big number for Medeski Martin and Wood
and Phish is very very good too.

Return to Forever is also very bumping you should look for their album Romantic Warrior and Hymn Of The Seventh Galaxy.

John Scofield's album Bump is a very good album.

also try Bela Fleck and the Flecktones not really guitar music but in the same laid back style you want.

Herbie Hancock's Head Hunters and Thrust