gridjam

Check out summer jazz workshops, get on forums and try to find people in your area that are into playing together, go to larger cities and check out live jazz. If you like what you hear, introduce yourself to the players and see if you can get a lesson. If they can't help you, there is a good chance that there will be someone in the audience (another musician) who can.
It's o. k. to use play-alongs but this is social music. You can only grow so much playing with people who are not listening to you.
:)