just plug the second one in and, after answering the warnings, do a sync.
Both iPad will then have exactly the same stuff on them.
Be aware though, that doing such will DELETE all the apps and music that was originally on the second iPad, unless already has music and apps that are the same as those being sync'd
I have my Ipad connected to my macbook and i want to take someone else's ipad and connect to it my ipad and be able to transfer music and videos over.. Is there anyway this can be done? I know there has to be a way to connect two Ipad's to one Itunes account.