Venice, the world's only pedestrian city, is easily walkable, and the absence of cars makes this a particularly pleasant experience. However, walking and standing all day can also be exhausting, so it is best to pace yourself. The Rialtine islands - the 'main' part of Venice - are small enough to walk from one end to the other in about an hour.
If you want to get around a bit more quickly, there are numerous vaporetti (water buses) and water taxis. The vaporetti are generally the best way to get around, even if the service route map changes frequently. If you are going to be in Venice for a few days visiting, it is a lot cheaper to use vaporetti than private water taxis. If you want to have a romantic ride along the canals, take a gondola ride.
ACTV runs the vaporetti and other public transport services both in the lagoon and on terra firma. Travel cards are extremely useful since the basic fare for one vaporetto journey is typically €6.50 whereas a 1 day travel card costs €18, and a 3 day costs €33. There are other versions available, including those offering discounts for youth under 29 year of age. Current rates can be found here:.
Since February 2009 the Venice Connected [15] website of the Comune di Venezia makes possible to book online (at least 7 days in advance) most services controlled by the town administration (public transportation, access to the civic museums, access to public restrooms, car park tickets, entrance to the Casinò and access to the municipal WiFi network covering the entire historic centre); the online prices vary according to the projected number of visitors but are always cheaper than the current on-site prices (and cheaper than with a Venice Card).
You can also get a Venice Card, which has various options that you can choose when you buy it (public transportation, cultural attractions, toilet access, Alilaguna, etc.) There is a 'Junior' version of the Venice that is available at a slightly reduced rate for those between 5 and 29 years of age. Note, however, that a Venice Card is not recommended for those with less than 3 days in Venice, as most of the top attractions are not included in the Venice Card. If you'll be staying in Venice for a week - get the Venice Card and enjoy travelling from island to island and exploring the various museums and churches it offers access to.
Maps are available at the vaporetto stops in the ticket booths. The map is quite reliable, and is free when getting a Venice Card (€2 otherwise).
Venice Cards can be reserved on-line for a considerable discount here: Keep in mind, though, that there are long lines when taking the Venice Card from the ticket booths. The Venezia St. Lucia ticket booth that offers Venice Cards is the one most on the right when you exit the train station.
Otherwise, take a walk! The city is not that big, and you can walk from one end to the other in a few hours. But it would take months for a fit person to discover every path in the city. Along the way you will discover marvelous art, superb architecture and breathtaking urban landscaping. Exploring the city randomly by walking is well worth it but also be prepared to get lost easily! Signs all over the city indicate the direction to the main attractions, "Rialto" and "San Marco", as well as the way back to the train station ("ferrovia") and the bus terminal ("Piazzale Roma"). These signs make it easy to have the "get lost experience" even as a one-day tourist.