Seeley G. Mudd Manuscript Library
Architecture School Archives: http://findingaids.princeton.edu/collections/AC137
Graduate School Records/Course Lists: http://findingaids.princeton.edu/collections/AC127/c0339
Department of Art and Archaeology: http://findingaids.princeton.edu/collections/AC140/c0172
Senior Theses, 1926-present: http://libweb5.princeton.edu/theses/index.htm
Firestone Library
Jean Labatut Papers: http://findingaids.princeton.edu/collections/C0709
Princeton University Digital Library
Historical Photograph Collection (Grounds and Buildings Series): http://pudl.princeton.edu/collection.php?c=pudl0038&f1=kw&v1=architecture
Rare Books and Special Collections
Architecture Collection includes the papers of individual architects and architectural firms, including such notables as C. Grant LaFarge, Robert Maillart. Also includes lecture notes and research papers of architecture professors, and archival history of Princeton University: http://rbsc.princeton.edu/topics/architecture