How to get to Sainte Enimie (Gorges du Tarn)

I will be traveling to Sainte Enimie in September, flying out of JFK in NYC.  Does anyone know the best way to get there once I land in Paris?  Is it better to fly to Montpellier or take a train?  Once I get to Montpellier, how do I get to Sainte Enimie?  Is there some other city I should fly into, or to take a train to, instead of Montpellier?  This will be my first trip to Europe.  I am not going through a travel agency as I will be doing volunteer work in Sainte Enimie.  Any advice you can give will be greatly appreciated.  Thanks