Modern Hagiography
Lives of the Saints by Alban Butler.
Lives of the Saints by Francis Weninger.
Lives of the Saints by Sabine Baring-Gould.
Pictorial Half Hours with the Saints by Auguste François Lecanu.
Stories of the Saints Fourth Series Saints of the Early Church by Mary Seymour.
Medieval Hagiography
Sozomen, Ecclesiastical History of the Church Book IX (pdf)
Art & Architecture
Warburg Institute Iconographic Database
Lives and Legends of the Great Hermits and Fathers of the Church, with Other Contemporary Saints by Mrs. Arthur Bell.
The Saints in Art by Joseph Maria von Radowitz.
Emblems of Saints by Which They Are Distinguished in Works of Art by F. C. Husenbeth.