I love love love venice! It has so much character! It is pretty neat to have everything on boats! It is expensive though.
Insider Tip:Don't use a map. Just wander around. The main attraction's routes are on the side of the buildings with arrows to get to them. The vaporettos can take you everywhere so I'd suggest getting a waterbus pass for however long you stayed for. It's worth it! Don't forget to activate it though! It is very expensive though so be prepared!