Got back from France on Sunday night. In response to recommendations at the beginning of the thread, I second the bit about the Beaune campsite. It's a good (four star) campsite, about 2km (i.e. walking distance) from the town centre and all the wine and escargots that has to offer. It's a Camping Municipal, so it's cheap, it's about 600km from Calais, and it's easy to get to the autoroute from. One warning - it's very popular with those who use it for an overnight stop, so either book in advance, or turn up before about five in the evening - especially at weekends. We were there a few nights, and on the weeknights they were full to camper vans but still had plots for tents, but on the Saturday night they were completely full.
As for comments on autoroutes - yup, they're great. And they take English plastic quite happily, though you might want to make sure you have a few different types in your car - at Christmas one of the peages was refusing Natwest cards, and we didn't have any other types in our car, but fortunately we were able to scrape together enough cash to get through. No such troubles this time.
We don't have a satnav, and never needed one. All our naviation was sone using a large (A2 size?) folding map, and the Lonely Planet Cycling France book. That said, the only town centres we did were Montpellier (which we knew, and were cycling) and Dijon, where entirely by chance we found the only free car park in town anyway (behind the police station, next to the railway).
