I would suggest picking up the book "All You Need To Know About the Music Business" by Donald Passman. It has a shit load of information about several aspects of the music business. There are several volumes of the book out because the music business is frequently changing.
This book is a great start. It gives you little gems of information. I would say most music business lawyers, artists, and managers these days have a copy of this book somewhere.
Of course, don't use this as the only source of info, seek out classes, get professional opinions, and go to conventions to learn about more.