The official drupal user and development community site - download the core and 3rd party modules here.

*The* place to read up on Drupal; documentation on getting started plus advanced topics - from stock installs to 3rd party modules.

A directory listing of websites powered by Drupal - great to see examples of what you can do with this CMS.

The best place to catch up on community news from around the world; the official Drupal feed aggregator