RK I have had garmin units since the 90's I have the map76, etrex and 60csx. The 60 is the best of the bunch given the features and the chipset it uses. I get reception in areas where other units fail.
For the gps units I have the following mapsets.
City Select, USATopo and the 24ktopo for national parks in the NE.
I use the city select for in car navigation and the two topo versions for off road. With the 60csx and a 1 gig card I have the ability to install maps from all three programs with room left over.
Over the years I have tried several waypoint and maps programs on my computer including the National Geographic program. The two programs that remain are Mapsource. Mapsource allows the transfer of the garmin maps to the units and lets me plan routes for long distance travel by car.
As a aside the 60csx with City-select does auto routing on the unit itself.
The program I use most is Expertgps
http://www.expertgps.com/ it is avalable for download on line with a 30 day trial. The cost is $49.50. You can download ariel,and topos for your region. It iterfaces with google earth. You can sync your digatal camera and gps unit and it will import your photos as waypoints. You can calibrate your own maps.
though I have never used the function except to play the program provides real time gps location when gps unit is attached and you have the maps on your computer.
for 50.00 bucks it is a very sophisticated program, great support and a very active forum. I would suggest you take a look.
Don't forget the extra batteries!