First I want to point out that there are many tutorials out there, this is just one of many. Also there are many ways of doing things. This tutorial will guide you through the steps I take when making skins, but this is not to say the very best and/or the only steps you can take.
My approach in teaching skinning in this tutorial is to provide you with information on how everything works before you jump into making skins. You could skip to Part IV and just start trying to make your skins right away and figure out things as you need. Feel free to use this tutorial as you need, skip past what you don't need to read and get what you need from here and there if necessary.