What is the best way to get around the city? For me, it is the Metro. Quick, reliable and cheap, as long as you are good with subway maps and directions the Paris Metro is easy to use. If you have taken my advice about where to stay, getting from the airport or train station to your hotel should be fairly simple.
From the airport look for the RER or “Trains” signs. If you have arrived in Paris by train, then look for the nearest Metro station.
From the airports, you will need to purchase a Zone 6 RER ticket to get to the city center. Even if you have already received your Paris Pass, travel with the pass is limited to Zone 3, so you will still need to get a separate ticket. I usually purchase a round trip ticket if I am going to be returning to the airport when leaving Paris. You can also go to the tourist office and ask to purchase a day pass if you are planning on using the metro again the same day, or need to use it if you are collecting your Paris Pass when you arrive.
If you have arrived by train, then you are most likely at Gare du Nord and can use your Paris Pass or a regular Metro ticket to get to your accommodations. Using the Metro system is fairly simple, even if you have never used a subway before. The signs are easy to read and well marked. Familiarize yourself with the line you want and direction you need to go, and what line to switch to if you need to transfer lines.
If you are coming from the airport, then you will be on the B-line (RER Blue Line). It will take you to Chatelet Les Halles where you can transfer to the #1 or #7 line to get pretty much anywhere along Rue de Rivoli. Just pay attention to which metro stop is closest to your hotel and then take the appropriate connecting line.
Be prepared that while there are often escalators leading out of the subway, you will most likely need to climb up and down a few flights of stairs while transferring lines.
I have found it it easiest to look for the closest exit when leaving the subway. They will be marked “Sortie.” Then, once you are out of the metro, figure out where you are and walk to tour destination. Sometimes trying to make sense of the different exit options from the metro have involved a lot of unnecessary walking up and down the subway tunnels. Unless they are clearly marked with a point of interest, I have better luck exiting at the closest staircase or escalator and using my mTrip map to see exactly where I am once I am on the street again.
If you are traveling with 4 or more people it can definitely be cost effective to rent a taxi, so do your research for your particular needs.