Organization is vital.  Try Zotero or Mendeley.

Become familiar with key words and other important terminology. Try using the database thesarus or other database subject headings.

"Mine" bibliographies.  If you find a good article on your topic, consider tracking down the resources the author(s) used for their research.  Try Google Scholar to do this!

The absence of research may tell you as much as the abundance of resources on a topic.