Two years ago I was travelling in France, alone, for 4 weeks.
Three days into the trip I bought a used city-bike, loaded my small pack on to the rack, and toured the rest of the trip. It was complete dork-touring: running shoes, street shorts, no toeclips, slightly large used helmet. It was great fun. I would ride for three days, then stay in a city for a couple nights, then take a train, with the bike, into another region.
Camping was not an option for me, as I hadn't planned a bike tour. But, I had excellent luck getting myself hotel rooms in the larger towns and cities. I'd pick something cheap from the Lonely Planet book if I could, usually no more than $18 per night (more now with the weak dollar.) They were sometimes shabby, but always clean, safe, and centrally located. Then I could just cruise around town on the bike and see everything.
I met lots of friendly people in France, especially the guy who bought my bike in Quimper, and his friends. I was wandering the city the night before leaving for Paris on a no-bike TGV, announcing to everyone "voulez-vous achetez un velo, ce soir?" and pointing to my bike. (I think I said it correctly at the time.)
I did meet two slightly rude people in Paris; I remember both of them. I was hoping Paris might be the first city without a rude person. No luck. But I did meet some very friendly and uncommonly helpful people while I was there.
Have a good trip!
Oh yeah.... food. I alternated between store-bought dinner in my hotel room, and finding a really nice restaurant with a 4 course prix-fix menu. Once again, the LP guide helped me find good restaurants that weren't too pricy. My hotel room dinners always went like this: baguette, mayonaisse, a few slices of good meat, fresh tomato, cheese, a carrot, an apple, a couple pastries for dessert, and a half bottle of wine. It was always satisfying.