1. On your dashboard, click Custom Tabs. Either on the left panel or via the manage tabs window.
2. Select what pages / groups do you your tabs to appear. Click on the drop down arrow and all pages will appear.
3. Click Create New Tab.
4. Add a title to your Facebook tab and put the link. Note that only secured site is allowed (HTTPS).
5. Once the custom tab has been created, you will see a folder appearing. You may do several functions such as publish, edit tab or delete the tab.
6. Click publish tab so that it will be published to your page in Facebook. Note that if you have several tabs, you may only published one tab. It will be automatic that the other tabs will be deactivated or unpublished.
7. You may now view your custom tab in Facebook.