Hi Chris B and other Swiss bound.
I think that this is the book I have, revamped, some other interesting books here too (I just googled AA Touring Guide Switzerland)
http://www.visitdunkeld.com/tour-switzerland.htm
Regarding routes to Switzerland I find the best route is on the autoroute, France, Belgium, Luxembourg, France turn on to the N66 through the Balloon de Vosges. The N66 is a good quality single lane carraigeway which crosses the scenic lowish mountain range by a series of easy hairpins. I then cross the Rhine to enter Switzerland from the German side. I would NOT recommend crossing into Switzerland on the French side near Basle as that involves driving right through the city centre which has lots roadworks. This route is on excellent roads and the autoroutes are toll-free as far as Switzerland.
Regarding stops. We tend to go against Caravan Club advice and stop at autoroute aires en route. We travel with the 'van ready to sleep, ie, floor space accesible,bed made-up, a little drinking and toilet water in the tanks. We have a cheap Lidl alarm on the door which screeches if the door is opened. We do use commonsense when choosing aires and don't stop at ones which are deserted. French and Belgian aires are very frequent so if we don't like one we drive on to the next. We've never had any problems in the 10 years of doing it.
Campsites we've stayed at enroute are
Camping Chenefleur, Tintigny. A pleasant rural site with 20 mins drive of the autoroute near Arlon.
Camping Acasias, Cernay in Eastern, France. Near the end of the N66 part of the route.
You can read my reviews of these sites here:
http://www.ukcampsite.co.uk/sites/reviews.asp?revid=7390
and here
http://www.ukcampsite.co.uk/sites/reviews.asp?revid=7389
In Switzerland we spent 2 very happy weeks a few years back at Camping Seergatli in Brienz. This is just a few miles from Interlaken. It is a tiny site right on the edge of the Brienzersee (Lake) we could, almost touch the water from our 'van. We didn't even book but just turned up and asked. There's another slightly larger campsite a bit further down the same road, also, on the Lake side. Brienz is a pretty little village with a range of shapes and excellent road, rail. bus and boat links in the village. We did look at the larger sites in Interlaken but found them very crowded - we're teachers and have to go in the peak season
All of these sites are in the Caravan Club "Caravan Europe" site guidebooks which I would highly recommend. I would, also, recommend the Alan Rogers "France" and "Europe" guides. All thes books are cheapest from Amazon, even cheaper than the CClub's own members' special price usually.