In order to import into Garmin Mapsource you need them to be in PCX-5 file in WGS84 format for a waypoint file *.wpt.
An interim step can be achieved by importing into GPS Utility (
http://www.gpsu.co.uk ) in a variety of formats. GPS Utility will accept simple file structures such as from Waypoint+ program (
http://www.tapr.org/~kh2z/Waypoint/ ) which produces a file structure as follows:
Waypoint, waypoint name, latitude, longitude, date , time , waypoint description.
Example:
Waypoint,D,10X215,34.064531922,-117.2959507350,11/23/1995,19:29:00,I10 X1215
Waypoint,DM,10X215,34.06548,-117.80632,11/23/1995,19:29:00,I10 X I215
Waypoint,DMS,10X215,34.06453,-117.29595,11/23/1995,19:29:00,I10 X I215
There are other utilities such as GT Filepro 1.3 (
http://www10.aeccafe.com/link/one_time_reg.php?link_id=413)
There is a utility "GeoConv" (accessible at
http://www.kolumbus.fi/eino.uikkanen/geoconvgb/index.htm ) which allows user defined input structures that can then be converted to a number of different GPS Mapping Unit file structures. Typically it requires:
ID, Description, Latitude, Longitude, Height although not all fields are manadtory.....
There are about 1,001 different utilities and there is a whole new trainspotting recreation now being built around Waypoints.
You need however to be careful in that there is a limit to the number of points that a Garmin Unit can accept which will probably be exceeded by the number of Speed Cameras....