Does anybody know how to take an online trail map create waypoints and download to GPS unit?

Specifically, I'm wondering how I could go about getting a trail map that I've found online, marking waypoints and putting it on my Garmin eTrex. Or creating my own trail in Google Earth.

I'm assuming your trail map is a paper map.

If you have some known reference points on the map you can scan the map and add it to Google Earth as an image overlay and try and match up your reference points as close as possible.

Once you've matched up your reference points you can then use the path defining tool in Google Earth to trace the path from the image overlay.

Save your path and export it from Google Earth and then put it on your Garmin device!

This won't be terribly accurate but if you somehow leave the trail and find yourself lost you'll at least know what direction to go to get back on the trail.

You can find more information about GPS devices and some great tips on how to use them on http://www.sourcegps.com