For a good map of the city, visit http://www.veniceonline.it/Maps/Maps.asp .
THE BRIDGES
Venice is brimming with bridges. The Rialto, a stone arch lined with shops that crosses the Grand Canal at about the halfway point, is the most famous. The Academy Bridge Ponte dell' Accademia between the Campo di San Vidal and Campo della Carita, also offers great views of the Grand Canal.
The Bridge of Sighs connects the interrogation rooms at the Doge's Palace (just around the corner from St. Mark's) with its historic prison cells. The bridge's name described the sighs of prisoners as they were led to their fate. You have to pay to walk inside the covered bridge, but can get a good, free, view of the outside from the Paglia Bridge (Ponte della Paglia).
THE GHETTO
The word ghetto originated in Venice where a gated part of the city was designated as the Jewish quarter from the 16th century until 1797. A commonly cited explanation is that the word stems from an Italian word "getto" associated with an old foundry in the area. A bas relief sculpture by Arbit Blatas in the main square Campo di Ghetto Nuovo in the Cannaregio district commemorates the deaths of Venetian Jews killed in World War II. In addition to walking around the area, you can visit the Jewish Museum of Venice for 4 euros, http://www.museoebraico.it/english/ .
THE BASILICA
The Basilica di Santa Maria della Salute St. Mary of Health was built after an outbreak of the plague in 1630. Its ornate dome is a feature of the city skyline. Works inside include art by Tintoretto and Titian. Located in the Dorsoduro district, across the Grand Canal from St. Mark's; take the No. 1 water bus to the Salute stop. Open 9 a.m.-12 p.m. and 3 p.m.-5:30 p.m. most days.
THE MUSIC MUSEUM
Classical music enthusiasts will enjoy the Museum of Music Museo della Musica a collection of instruments from the 17th to 19th centuries. The museum is in the Church of St. Maurizio, about a 15-minute walk from St. Mark's Square, and celebrates Venice's history as a center of instrument making. Open daily 10 a.m.-7 p.m., http://www.interpretiveneziani.com/en/museo-della-musica.php .