[Cerril]

JJ is sort of like AK... one piece of advice that I recall is true with both hands (moreso with JJ) - you decide preflop whether you're going to treat is as a drawing hand or a made hand. If you limp, expect to need to improve to win (and release if you don't hit a set like any other low PP). If you raise, try to win with it unimproved.

Now that's not just advice on how often it'll win but how you play it from the flop onward. If you play it like AA, then keep playing it like AA until someone who likely has you beaten decides not to believe you (as was mentioned, try to win the pot outright on the flop), but if you play it like 55 then just figure if it doesn't improve you're dead in the water (of course you also have the possibility of three unders flopping but even then you might be in trouble... not that you'd want to be so weak)