Index pages on History & Medieval History

Open Directory Project (http://dmoz.org/):History and Medieval History
The Open Directory project is a cooperative volunteer project of 'indexing'/subject classifying the web. Each category is edited by volunteer subject experts. Includes sections on national history, living history and recreation/re-enactment as well.
About.com  (http://www.about.com/): Medieval History
Each About.com section has its own 'guide' editor. While not all-inclusive, Abouit.com sites highlight really interesting sites, and include articles about the topic and commentary on the sites.
There's a email newsletter if you want to keep up with changes to the site. The Site Map is another good feature.
Yahoo (http://www.yahoo.com): Medieval History
Yahoo is the most well known index site on the web. It includes descriptive tags for many sites. It's getting a bit crowded, though, and the featured pages vary wildly in topics and quality. If you want the most educational, specific stuff, you can sift it out of here, but it's too dense for a quick browse.

Articles on researching history: