Did you know that you may not own the copyright to your published works? In the traditional publishing model, authors sign an agreement that transfers most, if not all, of their author rights over to the publisher. This agreement limits what you may do with your work:
If you own the copyright to your work, consider assigning a Creative Commons license. The six Creative Commons licenses allow authors and content creators to retain the copyright to their works, and allow others the ability to reuse, adapt, and derive new works from the original, for non-commercial or commercial purposes. The various licenses define what others may and may not do with the original work.
When assigning a Creative Commons license, consider:
All of the CC licenses allow others to share the original work in non-commercial settings, as long as the work is properly attributed and the source is credited. You may apply additional permissions to allow derivative works to be shared, and/or commercial use.
Author agreements can oftentimes be negotiated. Read over the agreement carefully.