Monergism
Classic articles and resources of the historic Christian faith. A navigation tool for finding theological resources on the web. Calvinist.
http://www.monergism.com/

The Online Theological Research Library
One (very) long page with links categorised by subject area.
http://www.angelfire.com/jazz/theological/

Theology Links
Links to theologians, online texts, journals, essays and papers, and organisations. No annotations.
http://www.fambof.nl/links/theology/

University of Pennsylvania Library: Christianity
One large page of the most important links.
http://oldsite.library.upenn.edu/resources/subject/humanities/religion/xian.html

Fides Quaerens Internetum
One of the earliest guides to Christian theology on the Net. Small. Leans toward institutions (schools, libraries, societies). Kept up to date, but almost no description of links.
http://people.bu.edu/bpstone/theology/theology.html

Computer-Assisted Theology: Internet Resources
Annotated directory. Strong on Biblical studies, historical theology, individual theologians, and publishers. Highlights best resources and new additions. Could take a minute and a half to load.
http://users.ox.ac.uk/~ctitext2/theology/

Believer's Web
Collection of articles with searchable index.
http://www.believersweb.org/

Biblical Worldview
Directory of authors, speakers, books and ministries that in the opinion of the site's authors teach a Biblical and Christian worldview.
http://www.christianworldview.net/

BILDI
[German, English] Search engine for texts, monographs, and journal articles. Provided by the School of Theology at University of Innsbruck.
http://www.uibk.ac.at/bibfu/bildi/

Phil Johnson's Bookmarks
Christian and theological links, with ratings and commentary from a Calvinistic Baptist perspective.
http://www.spurgeon.org/~phil//bookmark.htm

Catalogue of Articles
Collection of articles by leading theologians and philosophers.
http://brandon.multics.org/library/