... start with what you know and use that to identify keywords and to clarify concepts. Keep track of all of your research - write it all down.
Look at databases listed in related subject guides for additional and more specific resources.
Dissertations are gold mines. They contain original research and can lead you to understand problems or the field you are exploring, key figures in the field, research the dissertation built upon, and more difficult-to-find sources that their authors have tracked down.
You might want to start with MIT dissertations and theses through Dspace in case related research on your topic was done by MIT alumni. An additional resource to search is the Proquest's Dissertation and Theses Global database. Don't forget to mine the footnotes and bibliographies for related and valuable primary and secondary source leads.
Find new journal articles about your research topic!
There are a number of services via email and RSS for accessing tables of contents of new journal issues and research alerts (results of literature searches you construct, run periodically).
This site will provide links to these services, as well as an explanation of what RSS is and how it works.