its about creating a specular hilite really with a subtle bump map to catch the light.
I suggest this shader http://www.highend3d.com/maya/downlo...Skin-3002.html
Its pretty good and fast to render, its a blinn set up with a few extra nodes and it works well in MR too. It has a blue spec on it to get rid of that cg yellow looking hilite that can happen in specular areas. You'll just need to make a color, bump and spec map in order get the full effect