ok so there are two airports in paris but all international flights go to Charles De Gaulle. CDG airport is about 1 hour taxi ride from the center of Paris (60 euro) however your best bet is to use the metro.
Catch the "B" metro from CDG into the city, there is a special 10euro ticket from the airport but this is still the best and fastest way to get into Paris. Just follow the signs from customs to "B" RER Metro and within 10 mins you'll be on the train into town.(they even have these cool blue footprints to follow).
Also if like us you plan to stay in Paris for a while be sure to get the Paris Visite pass;
This can be bought in 1, 3, or 5 day pass lengths and covers the cost of travelling to CDG airport on the B metro line.
Getting around the metro sounds hard with luggage but it's not, save your 60 euro cab fair and buy the visit pass instead and basically travel on the metro for free the entire time you are in town.