"St. Mark's Square"
Beautiful square. Festooned with Japanese tourists standing in the scare-crow position waiting for pigeons to land on them. The Grande and the Florian are two cafes in the square. We had a double espresso in the Grande (£15) at 11am, and still couldn't sleep by 2am. Basilica and Campanile are both worth a vist. But the Doge's Palace tour stole the show for me. Well worth the visit.
"The Doges' Palace"
Do a tour. It was fascinating.
For the best view over Venice...a must if you're in Venice, I'd say.