Originally Posted by AugustFalcon
Basically, you can select multiple tracks in BaseCamp and tell it to join them. However, tracks are directional so the joins may not be exactly what you want. So, it is best to duplicate the tracks, put them in their own folder in BaseCamp and do the join on a couple at a time until you get the hang of it. Experiment, that's one of the best ways to learn this stuff.
Garmin also has some BaseCamp forums to ask questions in. Here is the link to the Windows version:
They also have a Mac version.
EDIT: here's a link to the Montana wiki, lots of good stuff there:
This is great. I shall continue mucking about with it!
thanks for your help Jack