Maemo Mapper v1.4.1 was released with in-program documentation. Use the "Help" button in the menu to access it.

Download and Install Maemo Mapper v1.4.1

There are many other minor additions in this release, most of them having to do with the main and context menus. For example, there is a new "Go to" menu that allows you to center the view on your GPS position or other locations. See the changelog for full details.