The Photographer's Guide to Copyright

[Jeff D. Welker]

A well written guide on this important topic that is absolutely free. All you need to do is follow the link below and give them your email address so they can send you the PDF document. Don't worry about sharing your email address with them. As they state on their website, "We won't sell or distribute your email address. It's protected by a gang of inebriated stripmall tattoo artists." 

http://www.photoshelter.com/mkt/research/photographers-guide-to-copyright