The Internet is rich in resources for medieval studies. Several sites are listed below; most of these will lead to many further sites of potential interest and/or usefulness.
Stanford University Library Medieval Pages.
Based on Stanford's printed library guide for medieval studies. Includes sections on Source Collections (including Authors and Texts), General Bibliographies and Guides, Encyclopedias, Indexes and Abstracts, National Historical Bibliography, Manuscripts and Early Printed Books, Electronic Texts, Images and Exhibitions and other websites. There are also subject bibliographies including inter alia those for Church History, Reformation, and Saints.
Research Tools of Medieval History.
An unannotated bibliography. Includes "Basic Tools," "Diplomatics and Paleography," "Great National and Other Source Collections," "Letters and Letter Collections," "Administrative and Legal Records," "Agrarian Records," "Fiscal Records," "Lists of Persons," "Records of Accounts," and "Manuscripts and Archival Sources."
Byzantium: Byzantine Studies on the Internet.
The focus is on Byzantine studies, naturally, but contains much that is of interest for the medieval church historian. Contents include information on the annual Byzantine Studies conference, course syllabi and outlines, shareware available over the Internet, bibliographies, full texts, images, articles, book reviews, list of discussion lists relevant for Byzantine studies and many links to other web resources.
Labyrinth: A World Wide Web Server for Medieval Studies.
Based at Georgetown University; intended as a "global information network providing free organized access to electronic resources in medieval studies through a World Wide Web server at Georgetown university. The Labyrinth's easy-to-use menus and hyper-text links provide automatic connections to databases, services, and electronic texts on other servers around the world" (to quote from the project's self-description). There are sections devoted to Philosophy, Theology and Church History but the historian of medieval church history will find much of potential relevance in other sections as well.
Online Medieval Sources Bibliography
This site provides a searchable bibliographic database of those medieval texts (including both non-literary texts such as letters, wills, etc. and literary texts) now available in printed or online editions and translations. The entries in the bibliography are annotated with information on genre, contents, original language, and information about the published version. Entries also include links to sources that are online.
Reference Book for Medieval Studies.
An effort by medievalists to produce an "online textbook source for medieval studies on the World Wide Web." The site includes an "encyclopedia" of original essays (including several on religion), resources for teaching, bibliographies, and an especially valuable, alphabetized (by author) list of full-text ancient and medieval sources, the ORB Library Connection.
Internet Medieval Sourcebook.
Located a Fordham University, this is another good site for access to full-text. There is a section of "Selected Sources" designed to be used as a teaching aid, a section of "Full Text Sources," a listing of sources by type, and a third section on "Saints Lives."
Guide to Thirteenth Century Theologians.
A bibliography of primary and secondary sources relating to about ninety twelfth and thirteenth century theologicans divided into "Secular Masters," "Dominican Masters," and "Franciscan Masters."
A good way of getting started on the Internet is to join an electronic discussion group relevant to a subject in which you are interested. Once you become familiar with the temper and tone (not to mention the daily volume of messages), discussion lists can be good sources of information not just for that particular subject but for the Internet itself.
MEDIEV-L is a very active list devoted to medieval history. To subscribe send the message subscribe MEDIEV-L firstname lastname to email@example.com.
MEDIEVAL-RELIGION, as the name implies, is devoted to religious topics in particular. Note the different command for joining this list: join medieval-religion firstname lastname sent to this address:firstname.lastname@example.org
In an attempt to cut down on the amount of chaff more specialized searchers have to wade through when searching the popular search engines on the Internet such as Yahoo! or Lycos, University of Evansville Professor Anthony Beavers and an editorial team of academics have created Ecole, a search engine limited to preselected web sites deemed by the editors to be scholarly and relevant to the study of the ancient and medieval worlds. Ecole can be found at http://ecole.evansville.edu/.