There are a variety of third party sites that offer Drupal-related information and functionality. For more general reading, you may also want to read the aggregated postings from hundreds of Drupal-related sites via Drupal Planet.
Drupal Sites: a directory listing of Drupal-powered sites with tags and ratings
Podcasts and video
Lullabot Podcast: a weekly audio podcast, 30 to 90 minutes long, about a variety of different Drupal topics, from geeky to super geeky
Groups.Drupal.org: home to user groups, module- and topic- specific working groups, as well as Drupal job postings
Drupal Contrib includes a lot of API documentation for the hooks provided by contrib modules
Note: these are a few selected resources that are maintained by the community. This is not meant to be a link farm or other resource to raise the page rank of the linked to sites, but rather a pointer to a handful of sites that have already proven themselves generally useful. Typically, personal or company blogs / sites are not included unless they have extensive "how to" or supplementary information. If you believe your site fits this criteria, feel free to submit an issue to the webmasters queue requesting you be added with details about your site. A site maintainer will review it and approve it if appropriate.