I have no direct experience with a Nuvi 200 but I would have thought it could save points perhaps a favorites. Hopefully someone familiar with this unit will comment.
Saving locations is a feature of most GPS receivers. In most cases these are called waypoints and will have a name, an icon, coordinates, elevation and some sort of a short basic description.
If no name is given units will commonly start with the name "001" and increment automatically for each successive waypoint like you desire.
Downloading waypoints is typically an all or nothing operation. Each manufacturer has their own data format but most will have an option to save the info to a text file. You may also be able to save them in a format that your county tax dept. can import directly into their GIS mapping.
The Garmin eTrexH is a good basic inexpensive model (link)
It only has a serial interface and does not come with a computer cable. The eTrex Venture® HC (link)
comes with USB interface and cable and has a color display as well.