Hello,
A very good and simple program to use for working with SKS is Art Weaver and is free. Here is a link to everything you need to know about the program and how to download it. It works very well I use it as a portable on my flash drive to do things at work as I need too. Saves me lots of time and I compare it to Paint Shop Pro by Corel.
Here is the link http://www.artweaver.de/index.php?en_version
Hope this helps you get started. Best of luck and keep skinning fun! 