Conclusion
Okay, so this page we've made is hardly likely to be winning any design awards. All I've focussing on in this tutorial is how to create some common layouts for your pages, demonstrating the flexibility of CSS design combined with lean, uncluttered XHTML. However, this skeleton can be used as a base for far more sophisticated designs by using background images in addition to the background colours. It's also worth bearing in mind that some very effective designs can be made with a minimum of imagery, using a well-balanced amount of borders and padding, and a tasteful combination of colours (see, for example, alistapart.com).
It's well worth getting some inspiration from some of the many design showcases on the web such as Design Meltdown or the CSS Zen Garden. There are more design related links in the Design section of the links page on this site.