I'm not sure if this has been suggested yet, but you should use a CMS. I use Drupal, so I recommend it over Joomla, but Wordpress might offer a simpler option for your needs. Drupal is a little more complicated and requires a lot of work to look good. Drupal's better for large community sites.
If you wish to keep things simple, I guess you could stick with what you have now, though. The content is more important than the site's appearance.