Transport in Paris (Ile-de-France region)
Paris is the center of the Ile-de-France region 50 miles (80 km) around. It has 5 transport zones with Paris' key sights within zones 1-2. Single tickets and passes for bus, tram, the subway, RER and SNCF suburban trains (the latter 2 may require a surcharge) are valid here. For instance, in Fontainebleau you can use a ticket bought in Paris.
Distant rides like to Chartres (85 km) are served by Grande Ligne trains with a separate ticket. But with a pass like Navigo Decouvert (zones 1-5) you can take a SNCF/RER suburban train to Rambouillet from which to transfer to Grande Ligne. In this case a ticket costs almost twice less than right from Paris, though taking a little longer.
You can get free public transport schemes of any form and size at any ticket office, Paris Convention info center and the Visit Bureau (Office de Tourism de Paris). Each subway station platform and entry also shows large schemes.
RATP's official website offers subway, RER and bus schemes downloadable as images or PDF (Acrobat Reader required). It also shows an interactive subway and RER scheme to help you arrange your route, plan its time and check a city map around a destination station.