Hugo_H
2
Jim,
Always difficult to completely answers questions, so here are a few clues which may help.
File structure of Garmin and where to place a map: http://wiki.openstreetmap.org/wiki/OSM_Map_On_Garmin/Mass_Storage_Mode
Maps can be constructed (or downloaded if you want standard areas) here: http://garmin.na1400.info/routable.php
if you have Mapsource installed on your computer, an easy way is to download the files for Mapsource, install the downloaded map on your computer (make sure it is in the folder where Mapsource stores its maps) and upload from Mapsource to the Nüvi.
Hope this helps, else post a reply, Hugo