Partly, jaggedness can be just in the shape of things.. If you look at the pixel art of masters like Henk Nieborg (www.henknieborg.nl), he favors certain shapes. Being careful about how your lines flow together (all of them.. think as if you had a lineart for each color.) can also contribute strongly to the impression of smoothness. It is easier to control flow with certain shapes and formations.

In my experience, you should try those things before going on to antialias a picture.
What I said then about AA is still good, if you decide it still needs antialiasing after adjusting the shapes and flows, then certainly make use of it.

Nemesis' tutorial seems to have disappeared (404 not found)

http://neota.castleparadox.com/aa_tutorial.html
http://www.rpi.edu/~laporj2/essays/aa/

Lawrence & pixelblink - I see what you guys are saying about the contrasts with the skintone.  I'll keep that in mind for the next piece I do and whenever I decide to rework this I'll go back and fix that.

sensation - would you happen to have any tutorials or anything that might explain how I get rid of the jaggedness?  Some of the highlights in the hair did come out too jagged and I tried to smooth it out in the beginning but it didn't work out too well. 

Help is definatley appreciated.

Thanks for the comments guys.

AAing isn't always the thing to do keep in mind. The real issue here for me is the lack of contrast in the skin tones as well. I'd like to see some darker tones mixed in.
On the plus side, I really like the expression and design. the hair turned out nicely as well.

try anti-aliasing this piece

Good work on the hair, but the lack of contrast on the skin doesn't match that of the hair, to me.