There is actually a dedicated shading model that was introduced in 4.5. And there is a documentation page on how to create realistic skin. Klick me.
I guess the problem is that you need really specific unwraps for characters and basically all of them have slighty diffrent shading and pore structure so there is not really a way to make a universal skin material.
As for the hair material, you can simply search the forums. There is a free anisotropic hair material out there. Klick me