Arnaud Bunel's Héraldique Européenne
Brian Timms - Studies In Heraldry
Early Blazon - Site dealing with early coat of arms from their onset to the end of the crusades.
Heraldica by François R. Velde
International Civic Arms by Ralf Hartemink
Hubert Herald, a site about heraldry and related subjects
Heraldica Nova Blog - a site of the University of Münster which aims to study medieval and early modern heraldry from the perspective of cultural history