Online resources

Remember when we got the <font> tag and finally could change our fonts and text colors? Or when someone came up with the idea of using one-pixel gifs in table cells for better positioning? We all made the mistake of spraying our documents with them, making any sane reuse of the code hard or sometimes even impossible.

Here are some resources to rectify old sins:

Markup related

Why use lists for site navigation?
A short article about the reasons for using lists in navigation. Also links to some examples.

Cascading Stylesheets related

W3C CSS validator
Check if your code validates according to the standards set by the web's leading authority
SelectORacle
Gives explainations for stylesheet tags — even the upcoming CSS3 specification
CSS2 specification
Dig deeper into the stylesheet specification itself

Online demos

Listamatic
List of examples of how to style lists for sleek navigation menus, even some nested examples are offered
CSS layout techniques
Examples of how layout can be done using clever markup and styling
Eric Meyer's css/edge
A must-see for those who missed it, Eric Meyer shows what we can expect more of in a recent CSS future
Zen Garden
User-contributed stylesheets has created a diverse gallery of "skins" for a defined XHTML template.

Other tools

Web Page Analyzer
Measures download times, file sizes etc.