The TDSB’s collection is very impressive: there some real gems in the collection, including student record cards and the complete records of the Home and School Association. There are, however, few finding aids. One was published in 1977 that is actually pretty good.
http://www.museevirtuelvirtualmuseum.ca/GetMuseumProfile.do?lang=en&chinCode=gusqm1
http://www.museumsontario.ca/museum/Museum-and-Archives—Toronto