The official website for tourism in France is www.rendezvousenfrance.com It is available in 17 languages. It has information on cities, regions, places to go to, events, special offers...

Almost every city also has an "office de tourisme".  If you use a web search, just type in the city you want to go to, and "office of tourism".  If they have a page in English, it will probably come up as one of the top choices.