A guide to web resources.
Stanford Encyclopedia of Philosophy
Non-profit project for a major encyclopedia.
Resources include a number of useful resources and study guide.
Episteme Links: Philosophy Resources on the Internet
Thousands of links to other resources.
Searchable database of basic information and definitions
The Labyrinth: Resources for Medieval Studies (Georgetown) -- Provides access to electronic resources in medieval studies. Note especially the International Culture: Philosophy and Theology link, which offers primary texts for Aristotle, Augustine, Plato and others
Philosophy Research Base
Annotated directory of thousands of resources covering most areas.