France has in total 185 airports, handling hundreds of domestic flights a day. The domestic airline links most of the cities making it really easy and cost effective to fly.
Air France is the national domestic flight carrier in France, offering flights between all major cities. The company also offers family, couple and youth discounts on domestic flights. If you book in advance you can also benefit from the reduce fares but with some restrictions.
If you arrive in Paris on Charles de Gaulle airport, make sure to transfer to Orly for your domestic flight. Air France operates a free shuttle for passengers between the two airports. The airports are also linked by train
When booking a flight pay attention to the other costs as well. Yes, the ticket is cheap but you also need to pay for the transportation to and from the hotel. So make sure to take that into account when you plan your budget for the trip.
Most of the domestic flights take in average about an hour so if you really on a hurry, flying is the best means of transport.
Most low-cost carriers fly to Paris and other cities in France, even smaller towns. So make sure to shop around before decided to fly into Paris. You might get a better deal if you fly directly into the city of interest.