Billy Joel – We Didn’t Start The Fire

How do you learn music theory?
What I am looking for is a textbook to learn music theory but doesn't assume you don't know how to read music. I can read music but just want more information about chord structures and more advanced items than learning how to read music. Any ideas of a good textbook?

Billy Joel We Didn’t Start The Fire (C) 1989 SONY BMG MUSIC ENTERTAINMENT … Billy Joel We Didn’t Start The Fire Pop Music Video