While the links provided are great and you should read through them (and all the other posts in the Hacking section) - just be aware there is no jail break at this time for the iPad2 on iOS 5.1.
We hear of work actively being done, but so far nothing. And no, no one knows when (if?) one will be released.
Oh, and jail breaks are always free. If you come across someone trying to sell it, it's more than likely a scam (in that it won't work) and you should avoid it like the plague.
Marilyn