Other
Netcraft: Directory of Web Server Home Sites
A list of links to many of the different types of web servers. Good for information about specific servers.
Virginia Tech
Spinning the Web: Setting Up World Wide Web Servers
Provides helpful information to anyone wanting to set up a WWW server. Also gives good general information as to how WWW servers operate.
Wikimedia
Wikipedia: Http
This site from the Wikipedia encyclopedia provides an encyclopedia article on Hypertext Transfer Protocols explains what they are, how they work, and the problems that Web designers can encounter with them.