The American Historical Association’s Archiveswiki “is intended to be a clearinghouse of information about archival resources throughout the world” designed mainly for historians, although others may find it useful:
Directory of Historical Textbook and Curriculum Collections, Judy Walker
(ed.), Chicago: Assoc. of College and Research Libraries, Division of the American Library Association, 2005.
Fifteenth to Eighteenth Century Rare Books on Education: A Catalog of the Title Held by the Education Research Library, Washington, DC: National Institute of Education, 1976.
School Collectibles of the Past, Lar and Sue Hothem, Lancaster, Ohio: Hothem House (Box 458, Lancaster, Ohio), 1993.
–Illustrates and has brief descriptions of a wide assortment of school artifacts.
Provides useful information and images of school items—don’t assume this is merely an antique guide.