Internet 101 was created for those who want to know just the basics. This guide will provide you with enough knowledge to have fun on the Internet, yet will not bore you with too many details. Think of this as a set of instructions...for people who don't like to read instructions!
http://www.internet101.org/
A guide to the Internet and World Wide Web. Good sections on mastering the basics and the Web at-a-glance.
http://www.learnthenet.com/english/index.html
A training resource for helping students learn about the Internet and World Wide Web. Links to important resources for further exploration and searching, including major guides.
http://www.december.com/web/text/index.html
Claims to be "the Internet's most comprehensive reference about the Internet." A little difficult to navigate, but the section on "How The Internet Works" is thorough.
http://livinginternet.com/