Great first sculpt man. You chose one of the hardest people to capture though... But you've done a great job so far. It started out very Easter Island-ish... but now it looks pretty damn good. Keep working at it.
It depends what clay you are using but isopropyl alcohol is good for smoothing out a sculpt. I think you want a liquid with 50- 70% alcohol in it and paint it on with a brush. I am starting sculpting too and that is an excellent first effort.