Taxis are convenient and not OVERLY expensive if you have several people and baggage to deal with. Expect to pay anywhere from 30-45 Euros to get from the airport to your Paris hotel, depending on traffic, destination and other variables. There are also some shuttle services, but I've never understood the affinity some people seem to have for them. The savings over a taxi aren't all that substantial and it creates the need to touch base with a specific driver at a specific time and place, leading to the possibility of delays.
Several lower cost alternatives exist, but you should be thinking about them when you pack.
For 12 Euros, the Air France bus will take to you to any of several points in downtown Paris where you can pick up a taxi, the metro (or if you're lucky, nothing but your feet) to get to your final destination. You can pick up this bus right outside the terminal at the first door, as you exit customs.
A very low cost, efficient alternative is to take the RER Line B3, for 7.85 Euros. You can grab the free ADP shuttle from the lower level of Terminal 1, get over to Terminal 2, where the RER station is located. The RER doesn't get stuck in traffic and conveniently links right into the Paris Metro system. That said, remember not to bring along things that will kill you on the stairs if this is to be your choice. You simply don't want more than you can conveniently and securely control.
A final, very inexpensive option to the airport from the Nation metro/RER station is the 351 bus, which stops right out in front of the Quick restaurant on the Nation circle, just a door or two down from Le Dalou brasserie. This works well from the Nation-area hotels I've suggested in this journal and buses depart 3-4 times per hour. Be sure to allow extra time to get to the airport, since check-ins tend to be rather arduous affairs. I generally arrive 3 hours before flight time and some airlines now require 2-1/2. Best Terminal 1 place to eat: Les Palmes, downstairs -- but they don't open for breakfast.