3-betting JJ against 50-70bb stacks ?

[SneakrFreakr]

Lately I've been thinking about spots like this as they tend to happen to me pretty often.

http://www.pokerhand.org/?898768

I've got not stats on the villain as he has recently joined the table. Do you 3bet preflop or just call? What's your plan with either option? Do you call a push? How do you play it postflop? How would his stats affect your play? And finally what do you do in the spot that I posted?

Quite a lot of questions but I hope I can get at least a few responses. Thanks!