Thread:Brandon Rhea/@comment-5583395-20121117085553/@comment-4674838-20121117091129

To protect a page, simply go to your page and click the arrow on the Edit button. You should see an option appear in the drop down menu that says Protect that will allow you to set the protection level of the page.

Note: only administrators can change the protection level of pages. If you aren't an admin, you won't see the Protect option in the edit drop down menu.

The process is described in detail at the help page: Help:Page protection.