With the increasing availability of research data for sharing, the need for reliable ways of finding and citing datasets has increased. Enter DataCite, an international organisation which aims to:

• establish easier access to research data
• increase acceptance of research data as legitimate contributions in the scholarly record, and to
• support data archiving to permit results to be verified and re-purposed for future study.

DataCite cannot provide you with a DOI, but they can provide you with information on how to get one. More detail about the service is here.