Creative Commons licenses are about sharing your work. The basic right you grant with one of these licenses is, that every noncommercial user can copy your work and give it to others, even over filesharing.
Other than that, CC-licenses have some restrictions, that can be applied:
- BY (attribution) - the creator has to be credited (all CC-licenses include this restriction)
- NC (non-commercial) - the work cannot be used in a commercial way
- ND (non derivate) - the work cannot be altered
- SA (share alike) - if the work is altered, it must retain the same license
These additions can be combined (except ND and SA, that are not compatible with each other). Naturally the creator of the work can give exceptions to all these restrictions. So if you don't want, that someone else alters your story or use it as part of a bigger story, you should add ND. If you don't want someone else making money with your work without asking you, you should add NC. In that example your choosen license would be CC-BY-NC-ND. Keep in mind, that non-commercial copying of your work is always permitted.
Read more about that here: http://creativecommons.org/licenses/
For more information about the implication, you might want to read the answers to my question: What are advantages/disadvantages to use a CC-license for your writings?.