There are many reasons to make your research data available for re-use by other researchers:
Visit re3data.org to find a repository for your discipline or contact your subject librarian for assistance in selecting a repository for your data.
Licensing your data allows you to define how your data can be used. Note: You may only grant a license if you are the rights holder for the data. Links to two commonly used data licensing options, Creative Commons Licenses and Open Data Commons Licenses, are included below.
For more detailed information, see "How to License Research Data" by the Digital Curation Centre.