Short FAQ on the topic:
Q: Which sites can be added?
A: You may add any site currently powered by open source content management system Drupal.
However, it is not in our policy to list sites with excessive adult, inflammatory or abusive content.
Q: How do I add my site?
A: Create an account with Drupal Sites Network (it's absolutely free). Just be sure you are logged in.
Q: What information do I have to submit?
A: Your Drupal site title, url, screenshot (highly recommended) and a short description for your project. Submissions in any language are absolutely ok, but there should be at least a couple of words in English.
Click here to submit your Drupal site!
All new additions are constantly monitored.