There is a wealth of transport options in Paris, from taxis to the métro to ferries, and everything in between. You will probably walk a great deal in Paris – it’s easy, quick, free and often very beautiful! Distances can be short and so walking is an efficient means of transport. For getting outside your neighborhood, however, you’ll want something faster.
The Paris métro is legendary and goes almost everywhere you need to go in the city. It’s also economical, especially with the weekly or monthly Navigo subscription pass. If you’d like to see what you’re zooming past, the bus system is also very good value and – unlike the métro – there are some lines that run all night. More specialized routes are covered by the ever-growing number of Parisian electric trams, and the RER train routes cross through the city on their way out to the suburbs – and airports! The Vélib system of public bicycles has been a huge hit, and cycling in Paris is relatively easy and safe. More and more areas have dedicated bike lanes. Not having to worry about theft, maintenance, etc makes borrowing from this ‘library’ of bicycles easy.
Parisian taxis are ubiquitous, if sometimes difficult to flag down – it’s far better to wait in line at a taxi rank or to phone ahead for one – and reasonably priced. Having your own car in Paris isn’t the best idea, unless you’re dependent on it due to special needs. Parking is a nightmare, traffic can be horrific and some French drivers clearly feel like frustrated Formula One drivers. If you’re absolutely set on having your own (motorized) wheels, then a scooter or motorcycle is infinitely more practical – cheaper, easier to park and you can weave in and out of the traffic jams if you dare!
Autolib’ is a nice alternative to owning your own car. In exactly the same vein as the Velib system, Autolib’ has stations of small, electronic cars thoughout the city that you can borrow on an as needed basis.
For longer distances, the national rail line (SNCF, http://www.sncf.fr) has local trains out to nearby towns (Versailles, Chartres, etc) and the super-fast TGV trains to most major cities of France. London and Brussels are tied to Paris via the Eurostar system (http://www.eurostar.com, in French, English and Dutch).
If you prefer to fly, Air France is the national carrier (http://www.airfrance.fr, in French and English) with their local airline, Régional, for short inter-France city ‘hops’. They are both quite reliable, although as is the case with any form of transportation in France, strikes do occur. They are usually announced well in advance so that you may make alternate travel arrangements.