hey all.. sorry ive been gone all week. ill try to clarify things--
re: greenstork
mapsource will, indeed, not be of use to you, since garmin stubbornly continues to release only proprietary maps that cannot be customized. to get the bike routes you need uploaded onto the gps, i can think of a few different ways to do it. basically, you just need some starting material:
1) the most obvious would be to enable tracking on the gpsr, and then ride all the trails. this could form the basis of a map, which could be used as-is or edited and cleaned up according to the methods i outlined in the first post. i know this obviously isnt useful for you now, but if you end up relying on the atlas during your trip, you could still do other bicyclists a big favor by saving the gps tracklogs and uploading them to a site like bikely.
2) you can try to scan and calibrate your bike trails from the fiets atlas. ive never seen this particular map, but as long as you have a real to-scale map with lat/long lines, scanning it and calibrating the image should be a snap. you want to start with as good a scan as you can make, with the map as squarely pointing north as possible. then you can use any number of freeware/shareware applications. i would recommend easygps, global mapper, or ozi explorer, which, if im not mistaken, should all allow you to calibrate the map without paying for the full versions. to do this, you just need to select the style of map projection used for the original map (usually printed somewhere on the map, otherwise you can make an educated guess), and then plot a few of the lat/long points. a great way to check if you got it calibrated accurately would be to use stitchmaps and google earth to make a satellite overlay of the same region. once you have the calibrated image, you can use a map program to trace a vector overlay. this is as simple as just tracing the trails with your mouse. if you use a full featured mapping application, you can then label the important roads/trails, add geographic details as polygons, etc. if all you need is the netherlands, i dont see this taking long at all.
3) instead of scanning the atlas and using it directly, you could just use stitchmaps to generate a detailed satellite photo of the region. the satellite images in google earth are definitely detailed enough that you can actually *see* all the bike trails. you can then refer to the atlas for names and whatnot, while tracing the routes you need over the google image.
4) you could try to hack the mapsource map. i havent tried this yet.. but i dont see why it shouldnt work. its probably not legal, and so isnt discussed on mapping forums (like the very helpful easygps forum, for example), but i bet its really not hard at all. if you can import the mapsource map into a map editor, then you could trace your trails on that.
in summary, i can only recommend you keep playing with the etrex. as you get used to taking it on rides and navigating around town, you will begin to realize its potential. get a 1-2gb micro sd card and log all your tracks. import them into the mapping software of your choice and play at editing them, drawing shapes, etc. then play at uploading these very rudimentary maps.
i have not successfully found any software that will automatically import *all* the data from a raster map into a vector map. BUT you can very easily import the topo information using global mapper. this is not so useful in some places (eg the netherlands) but it has been amazing for my trips around freiburg. last week i successfully found the highest point in the black forest using nothing but my etrex loaded with mapsource metroguide and my own transparent topo overlay (made in global mapper, then converted and uploaded with cgpsmapper and sendmap). it was one of the best bike rides of my life, but doing it without a gpsr would have been incomparably more tedious. these days i barely even plan a ride. i just go.
once more, in case it still isnt clear:
using google earth satellite images, yes you will still need to trace the vector map 'by hand' as an overlay. then you can export whatever you trace onto the gpsr. this isnt as tedious as it sounds, but it does entail some work. the software i listed, as well as similar mapping applications, makes this task a lot easier. once you become skilled enough, it is basically as easy as tracing over a map by hand with labeled points and shaded geographical regions, etc. you obviously wont be getting *all* the detail.. but i have only been using this method as a supplement to mapsource, which, is usually a lot better than i had expected for things such as bike and hiking trails. it IS possible to get a full-featured gps map without tracing, but it involves hunting down the data. sadly, most available geodata is usa-only. the major exception ive found is the topo data (available for free d/l with global mapper).
to get a sense of the two approaches,
here is a tutorial over whats involved in the 'automatic' approach. i imagine it works great, assuming one can find the necessary data. this next
pdf tutorial is off the global mapper help page, and gives a decent overview of the 'tracing method'. my own conclusion has been to use mapsource maps for most purposes, with the addition of topo data. for single-day rides, i havent found it to necessary to add extra bike trails beforehand, but its a lot of fun to view my tracks over the google earth satellite images afterwards, just to see exactly where i was and to edit the tracks into a more polished route, in case i want to ride the same way again.