This document provides instructions for adding a custom tab to a Facebook page in 6 steps:
1. Log into the Facebook developer site and create a new app
2. Name the app and select Facebook page tab as the platform
3. Customize the app by adding a domain, photo, and saving changes
4. Install the app on a page by copying the app ID and using it in a URL along with the domain
5. Select the page to add the app to using a dropdown
6. The custom tab can now be added to the selected page from the tabs menu.