As Uvah said above. I also don't have the link to the tutorial but someone will find this and provide it.
The tutorial is very basic but gives a good idea and it was great Kitty took the time to make it for new skinners.
As far as learning many more things I for one and others will answer questions. you however are going to have to commit to learning and just try many things on your own to see what does what. To start with you are permitted to use the Stardock Diamond skin as a template. Yes you will have to change images with your own, etc. I have been making windowBlinds for years and now and then still may find a setting I never knew about.
You will need some kind of image program and lots of time and patience. It certainly isn't cut and dry and trial and error are going to be a big part of it.
So lets get that tutorial link posted for you by someone so you know where to at least start. Nice you are interested as many are not anymore.