CDG to Invalides

RER to Gare du Nord, then the metro to Les Invalides. There's at least one line change, but rather than me explaining it in writing, just look at the ubiquitous metro maps when you arrive. But for Rue Cler, the Ecole Militaire metro stop is closer.

Tom's exactly right, of course. But you asked the wrong question: you'd probably be better-served by taking the metro segment to either Ecole Militaire or Tour Maubourg.

If you're packing light and can easily schlepp your own luggage: RER B to Gare du Nord. Metro line 4 (direction: Porte d'Orleans) to Strasbourg-St-Denis. Metro line 8 (direction: Balard) to either La Tour Maubourg or Ecole Militaire, whichever is closer to your hotel. The fare is €8.50. Keep your tickets with you until you exit the system.

If you have a lot of luggage: Roissybus to Opera (€9.10/person) and a taxi (around €10) from there to your hotel.

You can download the photoguide into your I-whatever and then use the turn-by-turn-spoken-directions feature. This is what the experts do so I do it every time I find myself at CDG.

Optionally, you can just follow the stinking signs which are all over the place.

Ritesh,

Using the RER B to Gare du Nord is perhaps the quickest option, as there are no "issues" with traffic.

You can buy tickets to the RER at CDG either from automated ticket machines or in the staffed ticket office. However, one point to note is that the ticket machines will ONLY accept the newer "chip & PIN" credit cards as well as Euro coins. The ticket office accepts the older "magnetic stripe" credit cards as well. Depending on the number of flights that are arriving at a particular time, there are often LONG queues at the ticket office.

More specific information is available at the parisbytrain website mentioned in an earlier post, however I wanted to provide a brief summary. There's also information available in both the France & Paris Guidebooks.

Happy travels!

Least stressful way:

Grab the express bus into Paris (it runs about every 15 mins and costs €8). You will need to have cash on you, the driver can make change for small bills. This bus is designed for airport runs and is very tourist friendly.

The bus drops you at Opera. From there you can walk down to the metro, or do yourself a favor and just grab a cab (figure another €5)straight to your hotel. You will have the rest of your trip to get comfortable with the Paris train system and you won't have to do it lugging bags along.