Software Options
Generally there are three options when planning a route on a computer.
The basic software bundled with the GPS. (MapSource)
A Gamin GPS will normally be supplied with 'MapSource Trip & Waypoint Manager' which covers the basics (placing waypoints, designing routes and tracks and transferring data to and from the GPS) but, with only a highly inaccurate basemap supplied, any routes you do design will usually be useless.
Unless your GPS came supplied with an expansion product, such as as the City Navigator maps, this option will prove to be a frustrating experience!
Free on-line route planning web sites. (Bikely, MapMyRide, GPSies)
For the financially challenged (who isn't?) there are a number web sites that will allow you to create a route by overlaying Google Maps with a point and click interface to plot your own route. My personal favourite is GPSies, but Bikely and MapMyRide are also very popular with cyclists. You can download the routes in the form of a GPX file that can be uploaded to the GPS via MapSource.
There are a number of reports of issues relating to opening the GPX files from such sites in MapSource, which is a problem if you want to use them on a Garmin GPS. To overcome this (and a number of other common issues) I have written a GPX track conversion tool which is free and might be of use.
Specialist route planning software. (TrackLogs, Memory Map, Anquet)
These are generally UK specific (Memory Map also has French maps), but are comparatively expensive. Their main advantage is they allow you to overlay your route on an Ordnance Survey 1:50,000 Landranger map. The level of detail is ideal for cycling and, as they all contain elevation data, can produce a handy route profile guide or allow you to visualise your creation in 3D.
Of the three I prefer TrackLogs, as the track creation tools seem a little more intuitive and can be uploaded to the saved track directly to the GPS. For anyone interested in this feature I have created a flash demonstration file showing how this is done with a 60CS.
