How do they do that with HTML?

The Bare Bones Guide to HTML

Writing Html

ColorMaker

The CGI Resource Index:
Programs and Scripts: Visual Basic

Put the weather On Your Site

Free Gif and JPEG Optimizers

Cedges HTML Cheat Sheet 

HTML Special Characters

CSS Tutorial

The Complete CSS Tutorial

site index

Webmonkey - If you can't find it here....

Tips, Tricks, How-to and Beyond

Eve's Realm -html help, graphics, etc.

PageResource.com
Tutorials in html, dhtml, cci, java

NetMechanic Tune up your website

HTML for the Conceptually Challenged And while you are there, check out Arachophilia which is was and by some still is regarded as the best free html editor; and then there is HTML-Kit and Nvu

Adobe Acrobat Free Reader
You will need this for some tutorials

HTML 4.0 Reference

Triple Colors
An excellent and very complete color chart which can be added to your Opera panels or Mozilla sidebars