Paris is served by three international airports - for more information, including arrival/departure times, check the official sites.
The major hub airport to the north-east of the city. It's notoriously confusing, so allow plenty of time for transfers. There are three terminals:
Terminal 1, Terminal 2 (which is huge and subdivided into 2A through 2G), and Terminal 3 (formerly T9). The newest exception is terminal 2G which is a separate building and is only reachable via navette/bus in 10-15min (bus leaves every 20min) so allow extra time. The free CDGVAL shuttle train connects the terminals together.