Yes, there is a TGV station at Charles De Gaule airport. It serves trains which travel from North to South France bypassing Paris. There is roughly one train every 2 hours, and it takes approx 2 hours to "Lyon Port Dieu" station.
The TGV trains from Charles De Gaule to Lyon are not the same ones that start at Paris Gare de Lyon, it is 'either-or', and there are fewer trains from Charles De Gaule than from Gare de Lyon.
I don't know what you mean by "The website", but www.voyages-sncf.com is the official site. You can look up times and prices there.
P.S. you save a lot of money by booking in advance. But, if you do so, make sure you allow enough time to gte through immigration (passport control), pick up your bags and get to the station, plus contingency for the plane arriving late. If you book an cut-price advance ticket and you miss the train by 1 minute, hard luck, no refund!