For 4.3.3 (including iPad2)
open Safari and go to
www.jailbreakme.com, follow directions and you are good to go!
For anything below iOS 4.3.3
The following thread was made for iPhones, but currently also works on the iPad 1. I have included the proper IPSW files in the first jailbreak paragraph. Currently the iPad2 cannot be jailbroken publicly although famed iPhone/iPad hacker Comex has successfully jailbroken it and will release his jailbreak soon.
http://forum.ppcgeeks.com/gsm-iphone...sh-thread.html