I am officially documenting this process, and hopefully this finds you well on your search for removing the submitted by Username on date text.

1. Go to your Global Settings (Site Building > Themes > Configure > Global Settings)
2. The box labeled Display post information on is where you can control which node the information is displayed on.
3. Check (or uncheck) the boxes.
4. Save.

Sounds easy, I know, but it's the small things like this in Drupal that can be easy to forget.

Well, not anymore.