Princeton University: An Interactive Campus History, 1746-1996: Includes building history, campus developments, key players and expansion periods.
Princeton University Current Campus Plan: Issued by the University Architect's Office.
Campus Architecture: Collections a: A resource list of related materials in the Library's Archives, Rare Books, and Special Collections.
PU Historical Photographs: Grounds and Buildings, 1850s-1940s.
Grounds and Buildings category on the Mudd Library blog (see specific posts by Mudd staff)
Cantor, Laurel M. 1983. “The Gargoyles of Princeton University.”
Cantor, Laurel Masten. 1985. The Spires of Princeton: An Architectural Tour of the Campus
The Daily Princetonian Larry DuPraz Digital Archive: This site contains images and text of The Daily Princetonian from its inception in 1876 through 2002. (For more recent issues, see: The Daily Princetonian.) A great place to search for local reaction to campus and town events.