Traditional copyright law allows content authors to reserve all rights. While this is still going to be appropriate in many cases, you now have the opportunity to make your content much more accessible to those who want to copy, distribute, edit, remix or build upon your work.
If you are comfortable with granting some or all of these rights, you can do so using a Creative Commons license. You specify the terms on which you want to make your content available and then provide the appropriate Creative Commons license alongside your content. Doing so makes absolutely clear to learners what they can and cannot legally do. How far you go will, of course, depend entirely on your business model and your educational philosophy.
First published in Inside Learning Technologies, December 2011