http://www.ncsa.uiuc.edu/General/Internet/WWW/HTMLPrimer.html
The Beginner's Guide to HTML describes the basics of writing in HTML (HyperText Markup Language). This site provides a primer for producing documents in HTML, the markup language used by web browsers such as Mosaic to display information. It assumes that you have access to and a general understanding of how a browser works. The information is very detailed and has links to each basic markup tag, other documents, in-line images, troubleshooting, sounds, animations, examples and more.