CSS

Covers 4 popular solutions, namely validating, joining, shrinking and compressing your markup source code for Javascript and CSS. Excellent HOWTO!

Tutorial on the art of choosing a color scheme for any website. Provides a list of practical tips and techniques a blogger should use while designing a color scheme.

Excellent screencast. Easy examples. In less than 5 minutes you'll understand why you want to build your site with CSS

I think this one is one of the best rounded corner generators out there!

Arguably the best resource to generate rounded corners! Do away with photoshopping rounded corners!

A cool technique to create a multi colored progress bar using only css and dhtml

One of the best introduction on CSS I've seen in a long time

Image rollovers are usually composed of two individual images; one for the default state and one for when the mouse is hovered over the image or link. However, it bears some advantages to use a single image by taking advantage of CSS image offsets.

Creating equal height columns with tables is easy. Of course we shouldn't use tables for layout. With CSS it's a little harder. If, for example, you create a three column layout by floating 3 DIVs within an overall container the result will probably look something like the following:

CSS lets you easily control your links look and style based on their current state. And with that I mean if the visitor is hovering their cursor on top of them, whetever the links have been visited etc.