Chris Sakkas writes a blog called Living Libre. In it he talks about the many ways that creative content can be shared openly. This includes free/open software, which I have used in the creation of Green Comet the novel, and Green Comet the website. It also includes Creative Commons licenses, such as the one I have used for the novel.
Chris has written a book called Share This Book, in which he clearly and concisely explains the concepts of free/open/libre creative content. Naturally, he has released the book under an open license – Creative Commons Attribution – CC-BY. You are encouraged to download Share This Book for free.
If you’ve ever wondered why I chose a Creative Commons license for Green Comet, Share This Book might be enlightening.