By plane: Venice has its own airport named after the most famous salesman and avid traveller. Marco Polo International airport (official abbreviation VCE) is located 10 km (6 miles) away from the city and receives the majority of Venice-bound flights, although charters sometimes land in Treviso - a city 29 km (18 miles) from Venice. From the airport you should head to Piazzale Roma, from where you can make your way to your apartment in Venice. Buses, taxis will get you there on land; waterbuses (vaporetti) and expensive water taxis will provide a much more glorious entrance to the city.
By train: Venezia Santa Lucia is Venice's railway station, close to Piazzale Roma and right on the Grand Canal which proves convenient especially with extensive waterbus (vaporetto) services available to newly arrived visitors. Some trains to Venice only stop at the mainland district of Mestre, which can be confusing, but in any case there is a bus or a waterbus that can take you to the old Venice from there.
By car: Venice does not have roads. The only cars you will see there are parked in the humongous Tronchetto parking lots or at Piazzale Roma, and yours would be no exception. Parking is compulsory! It is also not free: 24 hours will cost you around 25 euros, although discounts are possible for longer periods. There is no other way to make do with a car in Venice: it will be towed away if you leave it anywhere else.