The Creative Commons copyright licenses give everyone the ability to grant permissions to their creative work. However, they also give you a guideline on how you can use the work of others! Below is a visual breakdown of what each iteration of the CC License means, and how it changes what you can do with the materials.
To learn more about each license, you can check out the official CC breakdown here.
The Creative Commons website offers great tips on what to do once you have decided to apply a license to your work. Below is an excerpt of their recommendations from their website! You can view their full recommendations here.
If you are unsure which license best suits your needs, there are plenty of resources to help rights holders choose the right CC license. CC Australia has developed a flow chart that may be useful in helping you settle on the right license for your work. You can also read case studies of others who are using CC licenses. The CC community can also respond to questions and may have already addressed issues you raise. The CC community email discussion lists and discussion archives may be useful resources.