The international encyclopedia of revolution and protest : 1500 to the present. Edited by Immanuel Ness. Malden, MA : Wiley-Blackwell, c2009.
Trustee Reading Room Reference (DR): Firestone JC491 .I58 2009
Encyclopedia of the age of political revolutions and new ideologies, 1760-1815. Edited by Gregory Fremont-Barnes. Westport, Conn. : Greenwood Press, 2007.
Firestone Library (F) D295 .E53 2007
The Blackwell encyclopedia of the Russian Revolution. Edited by Harold Shukman. Oxford [Oxfordshire] ; New York, NY, USA : B. Blackwell, 1988.
Firestone Library: Non Circulating (Fnc) DK265 .B54 1988
The encyclopedia of the American Revolutionary War : a political, social, and military history. Gregory Fremont-Barnes, Richard Alan Ryerson, volume editors ; James Arnold and Roberta Wiener, editors, documents volume ; foreword by Jack P. Greene. Santa Barbara, Calif. : ABC-CLIO, c2006.
Firestone Library (F) E208 .E64 2006
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:
A few pitfalls to watch out for:
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 New Catalog.
Once you have a book in hand, read it. Alas, there are no shortcuts to this part of the research process.