Air France KLM announced last week a new low cost airline to debut end of March. It will offer 530 daily flights to 136 destinations within France and many European cities notably to Barcelona, Rome, Bologna, Florence, Geneva, Prague, Venice, Vienna Budapest, Dusseldorf, Brussels, Milan , Naples. This will make Paris a great point to jump start your European journeys.
Here is a selection of low cost airlines with flights from/to Paris :
Hop! by Airfance-KLM http://www.hop.fr
Easy Jet http://www.easyjet.com
Ryan Air (from Beauvais airport) http://www.ryanair.com
Air Berlin http://www.airberlin.com