AdvoCat (Catalogue of The Law Society of Upper Canada and the Ontario County and District Law Associations) http://library.lsuc.on.ca

Cornell Law School Library http://www.lawschool.cornell.edu/library/

University of Toronto, Bora Laskin Law Library http://www.law-lib.utoronto.ca/

York University Law Library http://library.osgoode.yorku.ca

For general (non-law) reference:

Toronto Public Library http://www.virtualreferencelibrary.ca

Library and Archives Canada http://www.collectionscanada.ca/services/index_e.html