The first Haw Ridge map was done in the mid 1980's on a MAC with MacPaint. Later, I used MacDraw. In the last few years, I switched to a PC with either Linux or Win95. Some maps and pictures were scanned in, others were done with FreeHand and a Wacom tablet. In '96, I started using a GPS to locate trail junctions and such.
The 3-D maps are derived from USGS data available on the Internet. The USGS DEM data is described and accessible via http://edcwww.cr.usgs.gov/doc/edchome/ndcdb/ndcdb.html You can "ftp via state", one DEM file is usually about 10 MB. (As of 1998, USGS is using the SDTS format and many 7.5min/1:24,000 data sets are available at USGS, and the file sizes are only 140K.) (Tennessee GIS data files, DRG quads, counties, DEM can be downloaded from here.) The program I use to generate the 3-D maps from the DEM files is 3dem50.zip It's a windows/desktop kind of program available from many PC ftp sites. I use http://www.acs.oakland.edu/oak.html to find such things. I then use a paint program (xpaint under Linux) to paint in trails, roads, cities, etc. I use xv to convert between different image types and diddle colors. The TN state topo map is from http://fermi.jhuapl.edu/states/states.html. Delorme's Topo USA is a nice set of US topo maps (50' contours) on 4 CDs, version 2 has 20' contours on 6 CDs. Better still is Delorme's 3-D TopoQuads, the state US GS quads on CDs. Also Maptech's TerrainNavigator provides USGS topo's on CDs GPS waypoints and tracks can be plotted on these computerized maps. The East Tennessee mountain bike web pages themselves were just built with vi starting in '93.
For another example of maps, visit Keith McFadden's N. Georgia mountain biking. His maps were generated from both ArcInfo and ArcView GIS (geographic information system) software from ESRI. The data (contours, transportation, hydrography) is primarily from the USGS 1:100,000 digital line graph (DLG) and enhanced where needed.
A GPS is handy for recording coordinates, for plotting trails on USGS quads, or for figuring out where you are. (Be sure to get a GPS that provides UTM coordinates.) They work with the 1 km blue UTM tick marks on USGS quads -- newer quads have superimposed UTM grids, see example. For hand-held GPS units, check out Garmin (the GPS II+ mounts on a bicycle!) or Trimble or Magellan or Eagle .) Garmin (Garmin V) and other vendors now have GPS units that support WAAS satellites improving accuracy to 3m. Note that UTM coordinates given on my map pages are based on the CONUS 1927 datum (that's what's used on the 7.5' quads), UTM zone 16. GPS accuracy for consumer units improved by an order of magnitude in May, 2000 when the US Govt. disabled "Selective Availability". Visit Mehaffey's page for lots of GPS info and product comparisons. Visit geocaching.com for interesting things to do with your GPS.
Google, maptech, terraserver, and topozone also provide online USGS topo maps. (Here is a comparison of topo maps/software cd's.) Roadmaps available from Census bureau's mapsurfer and mapquest.
Also see How To Make Mountain Bike Track GPS Maps tutorial
Waypoints of Tennessee landforms waterfalls, arches, balds, etc.