[Jason Strasser]

Ok, I'll have a rip at this. VERY GENERALLY:

With more than 10x the BB, open raise 3xBB from any position. If reraised, consider folding strongly. If called, play a set or overpair very aggressively, and sometimes take stabs at pots with one or two overcards, heads up, but not if it will commit your stack.

With more than 10xBB, call 3xBB or less raises with position, play a set or overpair hard, and back off otherwise.

If you have less than 10xBB, reraise all-in with JJ if its folded to you from any position. Go over the top all-in with JJ against most opponents opening raises, unless they are especially tight--or something suspicious happens, then fold.

In terms of calling all-ins, I don't think any good generalizations can be made. If it is not for a huge chunk of your stack, I strongly recommend calling. If you are getting bullied around, or whatever, this is a great hand to make a stand. If there is a raise and a reraise all-in in front of you, this is an easy muck. There are other scenarios too that are just useless to dive into under the "general" cloud.