Modern Hagiography
Lives of the Saints by Alban Butler.
Lives of the Saints by Sabine Baring-Gould.
The Liturgical Year by Dom Guéranger.
The Fairest Flower of Paradise: Considerations on the Litany of the Blessed Virgin, Enriched with Examples Drawn from the Lives of the Saints by Alexis Lepicier.
The Lives of Saints, with Other Feasts of the Year, According to the Roman Calendar by Peter Ribadeneira.
Medieval Hagiography
Writings by Saint Ildefonsus
A devotion to Mary from the Litany of Saint Ildefonsus
On the Lives of Famous Men by Saint Ildefonsus (free to borrow with registration).
Art & Architecture
Paintings by El Greco – one, two, three
Ildefonso Altarpiece by Rubens (Wikipedia Entry)
Warburg Institute Iconographic Database
Post-Biblical Saints Art Index
Legends of the Monastic Orders as Represented in the Fine Arts by Mrs. Jameson.
A Handbook of Christian Symbols and Stories of the Saints as Illustrated in Art by Clara Erskine Clement.
A Garner of Saints: Being a Collection of the Legends and Emblems Usually Represented in Art by Allen Hinds.
Lives and Legends of the English Bishops and Kings, Mediaeval Monks, and Other Later Saints by Mrs. Arthur Bell.
The Saints in Art with Their Attributes and Symbols, Alphabetically Arranged by Margaret E. Tabor.
Saints and their Symbols: A Companion in the Churches and Picture Galleries of Europe by E. A. Greene.
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.
Nihil sub sole novum 