If you want to try what seems like an advanced tool (to me), try going to the USGS site, click on maps, toss a couple of topo maps in your shopping cart, and then if you're using firefox (sorry msie guys) you can download them online right away. I continued on, after that, to give my credit card number so I'd get the paper maps sent to me too.
Open one up and you'll see its spacially-enabled, and will prompt you to download the free tool from http://www.terragotech.com/download/...=geopdftoolbar which will work with your firefox and acrobat to let you do lots of fancy mapping things such as building/measuring/marking a route using either satellite imagery or topo data or both, exchanging the data between geopdftoolbar and google earth and/or google maps.
I've done various mapping things now and then, but never quite like this - I was wondering if many had.
The one thing I'm finding is the same thing exists as has always: All of the mapping sources you try to correlate between are wrong in many points; you can't trust any of them. I saw that 20 years ago when correlating then-30 year old Mexican maps to modern ones, but am surprised that these discrepancies still exist today with our super-accurate GPSing.