You can only put something into the Creative Commons if you are the copyright owner.
Did some originality and creativity go into it, and is it recorded in some fashion?
No matter what the subject matter or medium, everything else is copyrightable.
Only the copyright owner may put a work into the Creative Commons. If someone else does, the author may sue to remove it.
The international standard is that all joint copyright owners must consent to any licensing of their shared intellectual property. The United States is an exception. While in the U.S. it is legal to license your shared intellectual property to the Creative Commons without the knowledge or consent of the other copyright holders, it is bad manners, unethical, and likely to discourage people from working with you in the future.
The U.S. Code (17 U.S.C. §§ 101, 201(a)) makes it clear that if a work had two or more authors who made substantial contributions that they meant to be part of a "unitary whole," then each of those authors is joint owner of the copyright for the entire "unitary whole." A written agreement stating joint ownership of copyright is common, and a good idea, but it is not necessary to establish joint authorship.
So the writer of an article for an edited volume is not a joint owner of the copyright of the whole volume, while the writer of several chapters of a textbook is probably joint owner of the copyright of the textbook.
How is authorship determined? If there is a written agreement, that is what determines it. Otherwise, here are some generally agreed-upon criteria:
To be an author (and owner of copyright,) one must:
Is your head swimming? Consult this chart:
"License Compatibility Chart" by CreativeCommons.org is licensed under CC-BY 4.0.
You probably want attribution, so ideally, you'll choose CC-BY. It will increase the likelihood that your work will be used and make a difference.
If you're incorporating CC-SA content, you will need to choose CC-BY-SA.
If you're incorporating CC-NC content, you will need to choose CC-BY-NC.
If you're incorporating licensed copyrighted content, that license might specify which Creative Commons license you're allowed to use.
If you have co-authors who are hesitant about putting the work in the Creative Commons, you might be able to compromise by using a CC-BY-ND license. It will prevent remixing, but at least it will make the content available.
The Creative Commons License Chooser is a tool that guides you through choosing your license and then generates the HTML and image you will need to use to mark your work with the correct license.
Creative Commons licenses are typically displayed in the footer of a work.
CC.org_cc_by_license.jpg by CreativeCommons.org is licensed under a Creative Commons Attribution 4.0 license.
Once you post your work on the Internet with a Creative Commons license, it is there to stay. It can't be recalled or rescinded.
However, you still own the copyright to your work.
When defending your copyright, Creative Commons or otherwise, you need to register your copyright with the US Copyright Office before you can take anyone to court. This is done online, and there is a modest fee.