I learned from a friend who helped me out with my first system. Just the basics of course. I also learned a little bit from trial and error, taking things apart and putting them back together, and I am learning a great deal from this forum. If you are really interested, I would suggest starting with a book. Get an idea of how cars electrical components work, then educate yourself on things like ohms law, voltage, amperes, etc., then you will fully understand how an audio system works, and how to install and "perfect" it. Then you can gather bits and pieces from this forum and talking to your local audio shop. Nobody knows it all, we are all a long ways from even knowing most of everything. Some people you might want to get opinions from are Zane, Ramos, Audiolife, Rangerman, Mykeys, etc.... They seem to be more up to date than I am.