Most historians publish their work in books. So, for many topics in history, your best starting point is a good recent scholarly book. The easiest way to find that book is to ask someone else who is knowledgeable about your topic -- for example, your junior seminar instructor or spring JP advisor. But a thorough search of the library catalog is also essential. Here are some tips on finding books about historical topics in the Princeton University Library Catalog.
Once you have a book in hand, read it. Alas, there are no shortcuts to this part of the research process.
While books are very important, historians also publish their work in articles in academic journals. And the easiest way to find journal articles is to search a bibliographic database that covers your topic:
Records on all subjects (especially humanities and social sciences) pertaining to East, Southeast, and South Asia published worldwide in Western languages. Includes chapters in edited volumes, conference proceedings, etc. 1971+
Print back to 1946 at Firestone Reference (DR) & East Asian Library: (GEST) Z3001 .B49. Prior title covering 1936-40 at Gest Z3001.xB8; Cumulative bibliographies covering 1941-65 at GEST Z3001.C94 & Z3001.C93.
Substantive, peer-reviewed, and regularly updated, the Oxford Research Encyclopedia of Latin American History combines the speed & flexibility of digital with the rigorous standards of academic publishing.