We are definitely on a budget, but will be travelling pretty light...is there any reason for us NOT to take the RER into Paris? I went to the CDG website, and it seems a bit complicated (my understanding is you have to take a shuttle to the RER?), but I'd much rather do that (it's probably much faster and definitely much cheaper--right?). Anyone have answers for me?

The RER station at CDG is located between Hall C of T2 and Halls E and F.
International flights often land at those 3 places, but mostly they are the preserve of Air France and its affiliates like Delta.

T1, which is some distance away, is used by other US carriers like US Airways.
If you land at T1 you will need a shuttle trip to the RER station.

The RER stops at Notre Dame and Luxembourg, which is convenient to the 5th and 6th Arrondissements.

From either stop you will have a little hike to your hotel, or whereever you are lodging.

If you are lightly loaded and have good legs, I see no reason not to take the RER. It is swift, does not have to compete with traffic for road space, and usually you can sit while you ride.

Perhaps someone will verify that Luxembourg station is a stop on the RER from CDG. My map indicates that it is.

We always take the RER from CDG to our hotel and have never had any problems. Since you are traveling light it should well for you too. Depending on what airline you are on will depend on what terminal you fly into, check the CDG website to see where you fly into (http://www.adp.fr/webadp/a_cont01_an.nsf/$$Affich@ReadForm&cle=X100130138.html)

Taking a shuttle is not a big deal, they run frequently and you'll be at the airport RER station in no time. Buy your ticket, should be around 7-8 euros and there is no advantage to buying a round trip ticket, the price is the same. When you board the RER you can't "screw up" all trains go to Paris. Check the boards above the platform, you see some trains are express, those are nice because they stop less and you'll get to Paris quicker. Last time we went to Paris it was under an hour and a half from the time we got off the plane to the time we excited the St. Paul metro station to walk a few blocks to our hotel.

Pick up a "Streetwise" Paris map (Barnes & Noble, Borders, Amazon etc.) they show streets and Metro/RER stops. The Luxembourg stop (near Blvd. St. Michel and Rue de Medicis is an RER B stop.) You have any questions about where to go etc. in the airport ASK someone! Everyone was very friendly and helpful to us.

Both times that we've visited Paris we've used the RER to get into the city. It's really not at all complicated - the shuttle from T1 if you need it is a free bus. It takes you directly to the area where you can buy your RER tickets and board the train. The only time I might consider not doing it is if you are arriving during the morning rush hour when the train might be very crowded.

If you each have one wheeled suitcase and a small carry-on you should be fine on the RER. And if you can't find the way to the bus at the airport, someone will surely help you. We weren't even lost and a nice gentleman asked us where what we were looking for and pointed us in the right direction.

Probably should have mentioned this first: we land in terminal 2-E of CDG, at 6am, and our hotel is across from Notre Dame so I figured the St. Michel stop would be close (someone else confirmed that it was close enough to walk).

If this amends any of your recommendations to take the RER please let me know.

Also, if anyone knows how to get from 2-E to the RER (is there a shuttle involved) I'd like to know. Otherwise it sounds like RER is the best way to go. Thanks for the advice!

I had problems getting my RER ticket from the automatic machines but you can use it at the booth itself. If your terminal requires you to take the shuttle, it will be obvious. The RER ride itself will take about 25 minutes.

Correcting the previous post: I had problems using my visa card in the automatic vending machine but ...

St. Michel is your stop.

If you're on a budget,the RER is the only way to go. If you look at the plan of CDG on the internet, you'll see that terminal 2E is within easy walking distance of the RER / TGV station.
http://www.adp.fr/webadp/a_cont01.nsf/$$Affich@ReadForm&cle=X5005A05A4.html

Forget about trying to buy the tickets from a machine (half of them are usually out of service) and get in the line in the ticket office; it moves a lot faster than you would expect.

If you haven't already done it go to this site and download an RER and metro map so you can do a little advance planning.
http://www.paris.org/Metro/

There's only one answer for you if you ar on a budget and that's the RER. The taxi will cost about 45 euro. We've always taken the taxi and even though it seems expensive it's more worth it for the convenience.

The RER is great and depending on the time of day is actually faster. They have self service ticket machines and as I remember they only take coinage. When we were there in the summer there was rather a long line up at the ticket wicket which we could have avoided had we had coins.

Before using the RER you may want to take a look at the State Dept's web site travel advisories- France. There they warn that the RER is a target of pickpockets who take advantage of jet lagged passangers. Use the RER from CDG with caution.

We are very touristy looking people who took the RER from CDG and had no trouble with pickpockets. It's easy to find the station as it is very well signposted in the airport, as is the shuttle. If you don't want to deal with the automatic ticket machines, go in the station and buy at a window. They move very quickly and are very helpful if you need information.

You won't have trouble finding a seat on the train at rush hour, but it will get crowded as it approaches downtown. You've got a seat so don't worry!

Keep your hands on your bags as you would in any large city. We didn't take the express; we took the local because it was the first train there. It was fun because it stopped at most of the stations so you could do some sightseeing. (It is not the most scenic view of Paris!)

If you have any question about whether or not the train will stop where you want it, ask someone standing nearby. Most people are happy to help you.

Yes, it stops at Luxembourg.

Enjoy your trip.