Plan a route on computer then download to GPSr

[+svenena]

I've recently acquired a GPSr (eTrex 30), and I'm still getting to grips with it. This weekend, I'm visiting a part of the country I don't know at all, and want to go on a walk, using my GPSr instead of a paper map, and pick up some geocaches en route.

 

What I want to do is somehow draw the route on an online map, and then import it onto my GPSr, and I can't work out what tool to use to do this.

 

I hope the end result will be looking at a map on my GPSr with a line showing the route, and a marker indicating where I am, so I know which way to go. I have basecamp on my computer, which seems hopelessly complicated. Can I do the above using this? I don't understand the difference between routes and tracks on it, but I presume I would use one of those? Also, I want to be able to mark the nearby geocaches so that I can see them on the map on my GPSr, so I know when I'm getting close, and can then switch to the compass screen. Is this possible? It seems like it should be. Help! I need a dummie's guide.