There are two airports in Paris : Orly (south) and Roissy-Charles de Gaulle (north).
Take the RER line B until the RER/metro station "Châtelet". Then change and take the RER line A until "Gare de Lyon" (direction Marne-la-Vallée or Boissy-Saint-Léger). In the Gare de Lyon, take the TGV for Annecy (for the time table, see SNCF).
Take the ORLYVAL which is the train service between Orly airport and the RER/metro station "Antony". The Orlyval leaves every 10 minutes and the journey takes approximately 8 minutes. From the RER/metro station "Antony", the RER line B will take you directly to the heart of Paris. Change in the station "Châtelet", and take the RER line A until "Gare de Lyon" (direction Marne-la-Vallée or Boissy-Saint-Léger). In the Gare de Lyon, take the TGV for Annecy.
You can have a look at the RER map.
You can consult the TGV on-line train timetable (and possibly buy your ticket and reservation) on this site (in english, maybe slow). There is roughly four/five TGVs Paris-Annecy (and four/five TGVs Annecy-Paris) per day. Note that you NEED a reservation in the TGV, but you can buy it (with the ticket) directly at the station on automatic ticket machines if you have a credit card (visa, mastercard, etc..). Of course there are also booking-office windows where you can pay in cash (and have to queue).
The easiest way to come to Annecy from Lyon Airport is to take a direct bus.
Unfortunately, there are not so many.
Booking :
Voyage Crolard : phone 33 (0)4 50 51 08 51
or on the web site www.altibus.com
Notice that there exists two TGVs connecting directly Lyon airport to Annecy (see SNCF web site).
If you cannot take a direct bus (or TGV) from Lyon airport, the second easiest way to reach Annecy is to take a shuttle Lyon-aiport —> Lyon downtown and then take a train at the Part-Dieu railway station.
Information on shuttle timetable and fares can be found on the SATOBUS web site.
You can consult the Lyon-Annecy on-line train timetable on this site (in english, maybe slow. If asked, Lyon is Lyon-69 or Lyon Part-Dieu).
For those reaching Annecy from Geneva, the most
convenient means of transport (apart from taking a car) is to take the
bus.
Avoid taking the train!
The bus departs from the Geneva Bus Terminal,
timetable available on its
web site
(choose Tickets-Reservation and then Regular Lines Region
Bordercross).
Geneva Bus Terminal is a few minutes from the Train Station (it
is very close to the Main Post Office: click
here for a Geneva map).
In Annecy, get off at the last stop: the Train
Station (see Annecy map: Gare
SNCF).
