Here are a few suggestions for books about copyright. You will find more books and articles within the Library's catalog.
Complete Copyright for K-12 Librarians and Educators by 
Copyrights and Copywrongs: The Rise of Intellectual Property and How It Threatens Creativity by 
Copyright Law for Librarians and Educators: Creative Strategies and Practical Solutions by 
Getting Permission: How to License & Clear Copyright Online & Off by