flyrules...
on my way to dubai, i flew from denver to newark on continental in august, and i had the same dilema...
there are tons of shuttle busses that make the trip...
i dont remember the name of the one i took, but when you land in newark, go to baggage claim, and look for the ground transportation counter.
ask about getting to jfk, and they will sell you a ticket on a bus...
it took me an hour to get to jfk on the bus.
we made only two stops before making it to jfk.
one was at the port authority, and thats where i changed buses...
then we stopped close to the empire state building after i got on that bus.
it was cool cuz we drove by the set of good morning america, and richard simmons was outside in a sparkly outfit!!
haha
so sit on the right side of the bus, and look out the window once you get on the second bus, and you might see someone famous!
hope that helps