Some examples of simple setups:

The pants only use the grey from the diffuse map to control Spec and Bump.

The shirt uses diffuse, spec and bump from the diffuse map.

The hair is special, It has lots of morphs, and the bangs have a life of their own. (combination of morphs and rigging). See that there are 2 Color Math nodes in there. I can draw the color from the Image Map, or from Color_Math or from Color Math 2.

And here a rendered example of some face and hair morphs and the 3 hair Diffuse color options used.

Best regards, Tony