Hi Pete, welcome to the board!
If you're going to Murano bear in mind that the glass workers start work at about 5.00am. So if you want to see glass being blown go to the furnaces early, and to the Glass Museum and galleries later.
In Venice I would recommend going to see Alex - 'Art of Venice' - whose shop is just off St Marco. direction on his website http://www.artofvenice.com/
Also in Venice, I would recommend seeing the Basilica for the floors, and the Doges' Palace for the ceilings! LOL
The Rialto Bridge is a must-see, and there are many excellent restaurants just under the Rialto beside the Grand Canal.
Enjoy your visit!