Modern Hagiography
Lives of the Saints by Alban Butler.
Lives of the Saints by Francis Weninger.
Lives of the Saints by Sabine Baring-Gould.
Medieval Hagiography
Art & Architecture
Codex Aureus of Saint Emmeram (not connected to Saint Emmeram, but in the library of the monastery dedicated to him and bearing now his name, see more)
Warburg Institute Iconographic Database
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.