Some GPS & Mapping links
Francis Cooke's Garmin essays - Basic stuff:
Living with a Garmin: Etrex Basic Setup
Living with a Garmin: Battery Runtime and Etrex Jitter
Living with a Garmin: The Waypoints Limitation
Living with a Garmin: Declutter the Page Sequence
Living with a Garmin: Living with Metroguide Maps
Living with a Garmin: Waypoint Naming and the Dakota 20
Living with a Garmin: Colour your Tracks and Routes
Top 5 GPS Tips (pdf) reprint of Arrivee article published Feb 2007
Some GPS FAQs web version of Arrivee article published Nov 2008
Dakota 20 review reprint of Arrivee article published Feb 2010
More Garmin essays - not-so-basic:
Living with a Garmin: Full Reset
Living with a Garmin: Track, Route or Autoroute
Living with a Garmin: Beat the 500 Trackpoint Limit
Living with a Garmin: Less is More
Living with a Garmin: Add Contours to your GPS Maps
Living with a Garmin: Struggling with GPX  &...  More GPX
Living with a Garmin: Screens you don't see every day
Living with a Garmin: Downgrade your Mapsource
OpenStreetMap and Mapsource Add OSM to your Mapsource collection
A Google Maps Workflow Create, Edit, Save, Share and Export a route
GPS Soak Test files to test your GPS waypoint capacity
  

Francis Cooke's Garmin Menu Map
(pdf, slightly updated July 2008)

Some other useful resources:
Jo Wood's GPS/Audax FAQ - excellent web page, introduction to GPS.
GPS Information .net big resource
GPS Passion big resource
GPS Review.net good up-to-date reviews, forum
GPSFileDepot some useful tutorials, forum
Groundspeak Forums GPS-related forum
Open Source GPS How To  ...  Info for Linux users
Garmin  ...   Magellan  ...   Lowrance  ...   Satmap 4 leisure GPS makes
Good tutorials on how the GPS system works:
www.trimble.com/gps/index.shtml
www.kowoma.de/en/gps/index.htm
Wikipedia on GPS

Desktop Mapping:
Memory Map    ...   Tracklogs    ...   Anquet
OziExplorer    ...   Fugawi
IGN    ...   IGN / Garmin French Basemaps
GPS Turbo open-source, cross-platform, desktop map display

Garmin:
MapSource   ...   and latest version Update (free)
**NB - versions 6.14 or later can be slower in use - see my note here
Metrowizz Autorouting wizard - beats the Metroguide incompatibility trap
Add-on contour maps courtesy of Scottish Mountaineering Club
WinGDB3 utility converts between Mapsource Route/Tracks, useful
MapSetToolKit utility to help add 'other' maps into Mapsource
Garmin latest GPS Firmware Updates (free)
Garmin Communicator browser plugin, connects Garmin GPS

 Online Mapping:
Google Maps
Multimap
OS Get-a-map
OpenStreetMap
Cloudmade OSM-based variants
Wikimapia

GMaps Pedometer
Bikely
MapMyRide
Toporoute
Routeslip
GPSies
Netkvik
EarthTools adds contours to Google mapping
BikeHike uses OS as well as Google mapping
Maps by The Hug uses OS mapping
CTC Maps good routes resource, parts need CTC membership/login

Utilities:
GPSBabel very good file cleaner and converter, also connects GPS, recommended but geeky!
ITN Converter another converter tool, not so powerful but easier
GPS Visualizer web-based GPS utilities, recommended
GmapToGPX to get GPX from Google Maps
EasyGPS simple clean-up utility, also connects GPS
GSAK (Geocaching Swiss Army Knife) more about waypoints than about routes and tracks
GPS Altitude Chart useful tool, requires Java.
Viking open-source GPS data management
GPS Trackmaker
GPS Utility not free, but very comprehensive
.