Web 2.0 how-to (and how not to) Design Guide

The author explains: "In this tutorial, I describe various common graphic design elements in modern web ("2.0") design style. I then attempt to explain why they work (i.e. why they have become common), as well as how, when and where you might use each element in your designs.... If I had to sum up "Web 2.0" design in one word, it would have to be "simplicity", so that's where we'll start."