By car

Several motorways give access to the South-West of France: A10, A89, A20 and A62.

By train

Agen has a train station for TGV (high speed train) and TER, with correspondences for Périgueux, Fumel-Libos, Penne d'Agenais
From the train station at Bordeaux, trains leave to Bergerac.
All required information can be found on www.voyages-sncf.com.
But please note that there are hardly any public transports (buses...) in this region. A car is really needed.

By plane

Bordeaux and Toulouse are two large international airports.
Bergerac is a lot smaller but has regular international flights to Great Brittany, Holland and Belgium.
(companies: transavia.com, ryanair.com, flybe.com). Car rentals can be found on each airport (Hertz, Avis...)