Early Christian Texts (online)

Early Christian Writings: a clearing house of (mostly) public domain translations of Christian texts from the first centuries CE, including some basic bibliography and publication information
Fathers of the Church (New Advent): updated (mostly) public domain translations of major texts from the "fathers of the church" (mostly orthodox writers from the first six centuries CE)
The Tertullian Project: ostensibly information on the third-century writer Tertullian, but also links to a wide variety of texts and studies about third-century Christianity


Early Christian art and archaeology

Princeton Index of Medieval Art: a vast collection of images and object from c. 500-1500
Arthur Urbano: Early Christian Art and Architecture: the public image database of a Providence College early Christian studies scholar from across Europe
Kurt Weitzmann, Age of Spirituality: Late Antique and Early Christian Art, Third to Seventh Century: open access publication of a lavishly illustrated collection of essays and images published by the Metropolitan Museum of Art in New York


Research Tools

North American Society for the Study of Christian Apocryphal Literature: a vast clearing house of information on noncanonical Christian literature stretching into the medieval period, including links to translations, secondary sources, and art and archaeology

JSTOR (only available from a BU terminal): access to books, essays, and articles on all topics, including ancient religion

ATLA Religion Database (only available from a BU terminal): articles and essays on religious studies and theology topics