Hey guys - great website:
http://www.bikehike.co.ukClick on "course creator".
It aligns an OS Landranger map and Google maps, and allows you to plot a route using both maps at the same time. If you click into google maps it does its stuff, finding the quickest route etc, then if you carry on clicking away on the OS map, you can continue to plot your route along your favourite byways. Once you've plotted you whole route, you can upload to your GPS. How great is that. I've donated to them, they deserve it. Finally some decent GPS software which is easy to use. Have fun!
Steven
S London & Surrey Group