Where can I learn more about Xs and Os? (NFL)

[TheRover]

Tell him what to look for, maybe?

These bookstores - they has books. A lot of people don't know that they carry books.

Any of the Pro Football Prospectus books are a good start. Of course, footballoutsiders.com

There are a series of books called (Year) Coach of the Year Clinics Football Manual or something similar that have transcripts of speeches by coaches at some annual get together thingy. I've never read them, but they look awesome.

Bill Ansparger has a few books about coaching defense.