Things to do in Venice during the weekends

Talking about the must-see/do things in this city is very difficult, because there is no city in the world like Venice.
Venice is built on 118 islands, with one hundred and fifty canals (the most important is Canal Grande), more than four hundreds bridges, without cars but only "vaporetti" (local transportation boats) and gondolas.
Venice is divided in six sections, called "sestieri" (Cannaregio, Castello, San Marco, Dorsoduro, San Polo and Santa Croce).

One of the must/do thing is a ride along the Canal Grande with a Vaporetto or a taxi boat. You can see hundreds of ancient and beautiful buildings and palaces (for example Ca' d'Oro, one of the most famous palazzo and one of Venice's greatest attraction) and the famous Rialto bridge.
Another must/do thing is walking in Piazza S. Marco.
After you must see the Basilica di San Marco, a marvel of Byzantine architecture, with gilded mosaics and marble expanses and inside the Pala d'Oro with two thousand pearls, emeralds, rubies.
In front of Basilica is the Campanile, the bell tower. You can take an elevator and see a spectacular view of Venice. In S. Marco Square there are many bars (ancient coffee bar, for example, Caffè Quadri, Florian, etc.) and you can take a coffee or a lunch break.