Brainstorm possible search terms for your topic. You may need to simplify long phrases by breaking them up into separate search terms or smaller phrases. It often helps to make a list of synonyms or related terms.
Consult background information. Take a look at books, newpaper articles, websites, etc. These sources often provide topical overviews, summarize basic concepts, and are filled terms that you might use in your searches.
Use bibliographies and subject terms. As you gather relevant books and articles on your topic, consult the footnotes and bibliographies of these sources for additional potential resources.
If you find books articles that are relevant to your search pay attention to the subject terms that have been assigned to them. This is an excellent way to identify useful search terms.
ANDs, ORs and NOTs. You will need to combine your search terms with connecting terms (called "Boolean operators"), such as AND and OR. Use AND between terms to narrow a search and OR between terms to broaden a search. See the video below for additional information on using Boolean operators.
Cite as you go. Even if you're not sure whether you will use a source, it's much easier to note the citation information up front than to decide you need it later. Citation tools like Zotero or EndNote can help with this process.