Modern Hagiography
Lives of the Saints by Alban Butler.
Lives of the Saints by Sabine Baring-Gould.
Miniature Lives Of The Saints For Every Day In The Year by Henry Sebastian Bowden.
Contemporary Hagiography
The Earliest Life of Blessed Marie by Jacques de Vitry (in English, here in Latin).
Art & Architecture
Warburg Institute Iconographic Database
The Saints in Art by Joseph Maria von Radowitz.