when i go to put oil in my jeep after i'm done driving it and when i take off the oil cap a little bit of smoke come out of the hole in the valve cover where the oil cap is, what would cause that.

 

A little smoke out of the oil cap after driving is pretty normal, the oil is HOT so some vapors are expected. If you had smoke puffing out of the cap with it running I might suspect piston ring problems, but if it's just a little smoke drifting out of the hole it's not a big deal. Make sure your PCV is in good shape too, a stuck one can cause too much crank case pressure