When building a new site in Drupal, unless you've got a large team of developers, one of the first things you're going to want to do is pick a new theme, i.e. a site template. Thanks to the efforts of hundreds of developers from around the world, there are over 170 themes for you to investigate for Drupal 6 (even more if you're stuck with Drupal 5), each one with its own set of traits.