I was helping out an organisation put up their Facebook Page and was asked to place a welcome message. Unfortunately, there is a character limit on the Wall, so the next best thing is to add it as a Note. But Notes is not one of the default Apps on the Page. Here is the easy procedure to add the Notes App.
Visit your Page, then click on the Edit Page button located at the right-hand side.
The left-hand menu will change to your list of options. Click on "Apps", which will bring up the screen below.