There's two ways to learn.
You could do it the way I did . . . try to figure it out on your own, break stuff,then have to go buy a manual and study it and find VW friends that will answer all those questions you have trying to fix the stuff you broke plus fix whatever it was you started out to fix in the first place.
Or, you can do it the way you've started out . . . get books and study, find people that have experiance and ask lots of questions before you attempt to fix something.
Both ways work . . . but trust me, my way can be VERY expensive and frustrating!
Welcome aboard!