If you can avoid picking up a rental at either a train station or an airport, you can save the pickup surcharge fee of 30€ to 60€. Expect to pay a one time road tax of about 10€ as well as a small fee for declaring additional drivers.
Automobiles running diesel not only get better mileage (kilometrage) but diesel fuel is widely available and usually costs less than gasoline. If you plan on picking up in one city and dropping off in another, Hertz and Avis usually have one way fees. Other companies probably have no such fees as long as the the pickup and drop off locations are within France.
Here is a list of rental companies operating in France:
If you plan on renting for three or more days, a rental broker can save you a great deal of money. Arrangements with brokers must usually be made before you leave home, have a 3 day minimum rental period yet offer great flexibility as reservation modification are as easy as a quick toll free call.
Driving is straight forward and no different than anywhere else actually.
