The main search tools for finding books, articles, databases, archival collections, and more at Yale (and beyond) can all be found on the "Find, Request, and Use" page of the library's website. Here are a few quick refreshers, but be sure to visit the page for a full overview:
Background or "reference" sources are a great place to start your research. Reference works include bibliographies, scholarly encyclopedias, dictionaries, handbooks, and other sources that provide overviews of topics and suggestions for further reading.
Oxford Research Encyclopedia of American History
A scholarly encyclopedia of potentially great use in the early stages of your research project. Each article has a discussion of the literature, including primary sources -- often a great starting point for finding more sources.
Link to the general collections of Cambridge University Press, including the Cambridge Histories and Cambridge Companions.
An extensive collection of annotated bibliographies often pointing to both primary and secondary sources.
Oxford Handbooks Online
Lengthy chapters in the Oxford Handbooks usually provide helpful overviews of scholarly topics and historical literature, along with suggestions for further reading. A number of the handbooks may be helpful depending on your research topic -- e.g., The Oxford Handbook of Canadian Politics, The Oxford Handbook of Canadian Literature, etc.
Subject-specific databases are a key resource for finding secondary literature, including the latest scholarly journal articles in the field, and the main subject databases for finding historical literature are:
Searching these databases will allow you to check for the latest scholarly articles, reviews of books, citations to book chapters, and more in a wide array of historical journals. Please note: the full text of articles will not always be available in these databases. If you see the "YaleLinks" icon instead of a PDF, click on the icon to discover whether we have online access to the article.