Where is the TI at this airport? Can I buy our museum passes and Pass Navigo carte there? Can I use my credit card? Do they also sell the Roissy bus tickets? I am trying to find one-stop shopping to save time. If I cannot buy the Pass Navigo carte there, which major metro stops sell them? The Roissy bus drops us at Opera and we need hope to use our pass to get to our apartment at Mo Etienne Marcel.
You don't say what terminal you are arriving at, but we located the TI booth as soon as we came out of baggage claim. They are easy to find, from signage or by asking. Yes, they sell you a museum pass and an RER ticket to central Paris, but not a Navigo. This you must do at a Metro, RER, or SNCF ticket window. You need to fill out paper work and have your 1"X1.25" "passport" type photo with you. Assuming you are arriving early in the week, you might want to take the RER to Etienne Marcel, on the #4 line from Gare du Nord. You can buy your Navigo at the CDG train station. It might be kind of busy there, but shouldn't take more than half an hour. If you're going to Versailles sometime that week, it will pay to get the all-zone pass right off the bat. If you just want the Navigo for central Paris, you can buy an RER ticket while you are at the window. The bus is 10 euro, the RER including the transfer to Etienne Marcel on the #4 is 9.50 euro. Or, if you want to get to your digs ASAP, just buy your RER ticket at the TI and head to the train station. In the end, its easier than the Roissy Bus, because if you use the bus, you'll get off at Opera, locate the Metro entrance, locate the #3 line platform, get off at Reaumur-Sebestapol and change to th #4 line anyway. RER is more direct and you'll be "in the sysytem" and save a whole 50 cents. Then you can get your Navigo at your leisure at any manned Metro ticket window.
I know, as in I fully expect, that this might go nowhere ;-) but I, My Own Self, would strongly consider walking from the Opera RoissyBus stop to my hotel...depending on exactly where from Metro: Etienne Marcel it is. It's about 14 blocks to the Metro Stop - great for working out those 'been-on-an-airplane-bus-for-approx-97-hours' kinked-up legs. Of course if it's raining up a storm...ummm, no. There's a Starbucks at Block 3 (and it's your turning point, too), if you're so inclined... Again, depending on where your hotel is...this might not be for you. Also, if you're bringing more than one bag this is definitely not for you! Also, look at a map (Google Maps would be great) and see how far your hotel is from the Metro: Sentier stop (Line 3). This stop is very close to Line 4's Etienne Marcel...it might be close enough to your hotel and it's only 3 stops from Metro: Opera - as in, only one metro line ride. FYI, the Opera metro station entrance is in front of the building, across the street (on it's own little island); the RoissyBus will drop you off at the side of the Opera building. I just thought I'd throw this alternative out there...now I'll prepare to duck-and-run ;-) Are you sure you need/want a Pass Navigo - you know its limitations? If you do want it, don't forget to bring your photos.
Here's my two cents. CDG to your hotel: skip the bus. take an express RER to Les Halles and walk to your hotel. Carte du Musee: They are sold at the TI's at CDG. If you really want to save time, order it online before you leave. parismuseumpass.com credit card: limit your use of credit cards because of the fees you'll be charged. Make maximum withdraws from an ATM & use cash. Having cash will also allow you to buy RER tickets at the airport from a kiosk instead of waiting in line. Navigo: I'd think long and hard about choosing this option. They are good Monday thru Sunday, so if there's a weekend in the middle of your trip you'd have to buy two. The Paris Visite pass is a waste unless you can use enough of the discounts to make up for it. My suggestion for getting around is a Moblis ticket. its a daily pass that's 6,60 euro per day for the city or 10,80 if you're going to Versailles.