Get a map of Venice with the water bus routes. You can see major parts of the city just by getting on and traveling the canals around the major islands.
Just sit in St Marks Square and watch the pigeons, listen to the music, watch the people go by.
The Venetian glass is beautiful.
Be careful about the time of year you go to see Venice. It is under water some times. Planks are put out to walk when the sidewalks are not walkable. If you go the right time of the year, it is a beautiful city and well worth the trip.
Find a website that actually has some information on what to do, not just idle observations and activities that you can do anywhere.
Here is a mildly useful site (http://www.veneto.org/lin...)
