Found this page today:

http://www.eatel.net/~amptech/elecdisc/

It has an INCREDIBLE amount of information on every part of a car audio system, down to the level of individual electronic components and basic principles of electricity. The detail it goes into is often daunting but it makes very sure nothing is left unexplained. Definitely check it out but don't spend 12+ continuous hours reading it like I did today.

Borislav