Here is a simple way to texture your model and move on to other things. You will be using the materials that you applied in the make human program before exporting your model. If you exported your model as lady1 for instance there will be a folder in your makehuman/export directory called lady1, inside the lady1 folder is a folder called textures. With that out the way lets get cracking.
Your model should be coming to life. Human skin is some what oily and a little reflective so to fake this add another mix shader and then a glossy shader. Set the roughness value of the glossy shader to .5 and the factor value of the mix shader to .1. Next you have to mask the clothes. so you add a mix shader and a transparent shader. Then add the mask texture, connect it to a color invert node then connect that to the factor value of the mix shader. and you are done with the skin.
It gets a little easier from here. The next material is the mouth. as in step 1 you will be adding a mix shader and a transparent shader. The diffuse shader on the bottom and the transparent on the top. Add your skin texture to the diffused shader and the alpha to the factor value of the mix shader. To make the eyes and the eyebrows easier to do you will group the texture node the transparent shader node the diffuse and mix shader nodes together. You hold down shift and select each then press control G and move to the next material slot.
Here is the new node group.
Move on to the eyes. Select use nodes. Delete the diffuse shader. Select add group. Connect it to the output shader and you are done with the eyes.
Repeat the above procedure for the the eye brows.
The invsio material is a mix shader diffuse and transparent shader. and for the red green and blue material just click use nodes
Your model is ready to render except there is no hair. You can use the hair mesh if you created the model in makehuman with hair or you can strand render hair in experimental mode. For this I will use the hair from make human.
With the hair mesh selected we go to materials and use nodes. Add a mix shader a transparent shader and a diffuse shader.