Could someone please confirm my assumption on the purchase and use of the 10 carnet white ticket+t. When we arrive at CDG, we buy the 10 carnet, and we use one ticket for the RER and then get off and get on the Metro to our hotel with the same ticket??? In some of the reading I have done I get the impression that they can't be used from the airport. Also do these 10 packs have different zone options, or are they good for all zones. I understand that I will only need zones 1 & 2, but perhaps this is where the airport falls out of favor. We will only be in Paris for 1/2 of Sunday, Monday, and Tuesday. Thanks for your assistance.
Yes, you can buy carnets for a range of zones, but that won't be to your advantage. The standard carnet is good anywhere the Metro goes (some lines end in zone 3), on the RER in zone 1, on buses & trams (except for T4), and the Montmartre funicular.
A single ticket on the RER B to central Paris costs 8.20€. It is good for unlimited transfers to the Metro and/or other RER lines until you exit the system and will get you to within a few blocks of any hotel in Paris.
You may want to consider getting 1 ticket from CDG to Paris (it will allow to change over from RER to Metro) and purchase Zone 1/2 tickets/carnet) for travel w/in central Paris. When I priced out the options some time ago, this was best price option and allows travel between all the desired Paris locations.
The ticket for the RER is a separate ticket from the ones you purchase for the Metro. After getting off the plane and going through customs follow the signs which will lead you to a ticket booth where someone will assist you(in English). Purchase your RER tickets and a carnet(if you are going to use the Metro that much and you probably will). Take the RER to a transfer spot which will depend on where you're staying in Paris. Then use your Metro ticket to get on the subway. Be careful going through the Metro with luggage. The gates that open after you insert your ticket close very fast.
Tim and sheryl are correct with the information that the RER ticket you purchase to get into Paris from CDG (at 8.20 Euro each) is good for transfers into the Metro system upon your arrival in downtown Paris...so you won't have to use a separate Metro ticket to get to your destination. Your carnet of 10 Metro tickets will be good for the 2 1/2 days you have in Paris....they can be used on the Metro or on the RER within Paris. See http://www.ratp.info/informer/anglais/index.php for maps of the Metro (the tickets are good on all lines to all destinations) and the RER (look for the break in the coloured lines....the station right before the break is as far as your Metro ticket will take you.) You may want to purchase your RER ticket back to CDG as you arrive.....you can use it to take the Metro to the RER, then out to CDG.