Bus
Buses are by far the best way to get around the city for tourists. The most up-to-date bus maps can be bought at news kiosks, with regular bus services running 5.30am-midnight daily, every 10-45mins, depending on the route. The doors for boarding (usually front and rear) and alighting (usually centre) are clearly marked, and a sign at each bus stop displays the lines and routes they take.
Note that the express buses make few stops along their route: check before boarding so you don’t get whisked past your destination. Keep your eyes peeled for the small fleet of electric minibuses too, which serve the centre by navigating centro storico alleys too narrow to accommodate regular buses.