Sounds easy. Read a couple of pages in the book and go at it. Well sorta like that. The Garmin manuals are fairly simple, but woefully incomplete. In order for a track to be transferable from one Garmin receiver to another it must be of a compatible size and configuration.
There are two types of Garmin tracks: Active Tracks and Saved Tracks. The GPSMAP series of receivers all include a provision to save tracks from the active log and also to load saved tracks from a computer. The active memory varies between 3000 and 10,000 points and includes time and altitude stamps in the recording. Frequency of track points can be set to a given time or distance interval. More about that later. When the GPS is turned off or looses reception, the track sequence is closed and a new one started. So when you download the Active log to a computer it begins a new track at each break. The breaks are not visible from within the unit itself.
Within the GPS, the Active Log may be used to save a track. When the entire Active Log is saved it will be condensed to fit the maximum size of a Saved Track. This size is either 500 or 700 points, by model. Be aware that when a track is saved, the time, speed and altitude stamps are lost. This and the size limit is a big drawback of sharing saved tracks. The advantage is that Saved Tracks of no more than 500 points are more or less universal and can be read by almost any receiver. Streetpilot and Quest receivers do not use Saved Tracks. They can load and use saved tracks from a computer, but only to the Active Log. To save a named track to these receivers, the tracks must be renamed to: "ACTIVE LOG, ACTIVE LOG 001, ACTIVE LOG 002, etc". The Active Log is treated as a sequence of tracks which can not be handled individually. New logs are simply appended to old ones until the memory runs out.
I've found the very best way to share tracks from a GPSMAP type unit is to share both the Active Log and to save condensed tracks at a 500 point maximum. This ensures that all receivers will be able to use your logs with a minimum of hassle.
Here's how you do it..........easy as pie
1. Clear the active log. Go to the "Tracks" page from the main menu on your GPS. By default Garmin units roll over the active log and record continuously. The unit replaces the oldest data with current points. This is fine, but you'll want to make sure the tracking feature is turned on and clear what's already in the log at the starting point of your ride. If you began recording prior to the intended starting point its OK, but you will then need to edit either when you save it or on your computer after it is downloaded. Best to start fresh at the trail-head.
2. Set the record method. Click "Setup" from the Tracks page. By default the unit uses "Auto" with normal intervals. Either distance or time intervals can be selected. If you want to save tracks and clear the active log at the end of every day, then this setting should work fine. The advantage of "Auto" is that it will use more points when speeds are low with numerous changes of direction, and less points when your moving fast and straight. As an alternative, I like to use time intervals and ration the Active Log over the entire trip duration. Selected interval then depends on the length of the trip and the capacity of your track log. For a quick half day outing on rough trails, four hours will fit into 1000 points at 15 second intervals. Either method works well. I don't recommend distance since it won't work well when your changing direction frequently.
3. Adding features and waypoints. I like to mark features along the way. This is very helpful in understanding where gas can be found, nice views or lunch spots, hazards, hard to find turns, etc. To do this on most Garmin units, you just press and hold down the "Enter/Mark" key for one second. When you do this the unit pop up a screen with name and symbol information. I don't like to take time for this on the trail. I can usually remember what a mark was after seeing the location on the map at home. So I ignore that screen. It numbers the waypoints in sequence and goes away even if you don't press OK. Then at home I edit the names form the computer, keeping them in numerical order for ease of following them in the list.
4. Editing Tracks within the GPS. If you forget to clear the log before starting the day, recovery is not so hard. You can save just the part of the log that includes your intended ride. Click save, then when prompted, click "no" when asked if you want to save the entire track. The unit will prompt you to find the beginning and ending point on the map. I try not to do this because its slow and not so easy with bad eyes. After you save a track, it can not be edited from within the GPS. You can also use this method if you miscalculate or forget to set an appropriate resolution and the Active Log fills too fast. Just isolate sections of the ride. Save them each to their own Track. Then clear the memory.
5. Editing Tracks on the computer. When you get home, connect the GPS and upload your newly recorded tracks into the computer using Mapsource. If your tracks overlap, don't start and stop in the right place, or contain errant data points you can edit them in Mapsource. Just go to the Tracks tab, right click one of the tracks and "show selected track on map". Then using the arrow pointer right click the track point at the beginning or end of your route that you wish to delete. Click "track properties". This will open an edit window. From there, you can delete any points that don't belong in your route. Just start with the point you picked on the map. Highlight (to the beginning or end) the points you wish to erase and hit the delete key.
You can also edit the Active Logs to combine tracks that have become separated by interruptions to the signal. By cutting an entire section and pasting it into another section the fragment disappears. This effort cleans-up a lot of weird stuff and can make the tracks much easier to use. By the way, all of this stuff applies to tracks you download from here and still need cleaning.
After doing this I edit or insert waypoints with the flag button similarly to what is described in the section above. Keeping them in sequential order with a name that starts with number 1 is the easiest to follow. Now is also a good time to delete waypoints from other rides that may have been in memory on the GPS. I also generally delete any routes or map titles that may have uploaded in the process. These are of very limited use for sharing and may not work from a GPX file anyhow.
6. Saving the file from Mapsource. After editing the file, it needs to be saved and named in the GPX format. Pick "Save As" from the file menu. Then in "File Type" pick .GPX from the drop down list. I suggest naming the file by starting location. You can also include the length and say loop in the name if you want to. Now your file is ready to attach to an ADVrider post from within the forum region. You must be using Mapsource 6.0 or above to create or open .gpx files. If you don't have this version you should get a free upgrade: Mapsource 6.xx
That's about it. Go out and "Make some Tracks!"