This is a nice tutorial:
It also works for horns, tails and whatever.
I fear that I can't be your "teacher"
So just tell me where you encounter problems. Skin textures are edited with Photoshop or Gimp. I guess you can paint textures directly on the model but if aren't an expert you can use Gimp, and then install the plugin I talked about. There are a few files for a skin texture, but you probably only want to mess with the diffuse one.
Edited by Derok, 03 March 2016 - 09:28 AM.