Any must do tours of Venice, or just self tour?

The free tours listed should keep the kids interested, they're very informative and if you do multiples, cover a lot of Venice.

http://www.venicefreetours.com

By bell tower, I'm guessing you mean the Campanile? There's also the bell tower in the Church of San Giorgio Maggiore. I'd recommend going ovrr there for wonderful views of the waterfront in front of P. San Marco. It's only a short vaporetto ride from the S. Zaccaria stop. We've never found a need to buy tours in Venice. Just wandering the back streets and peeking into storefronts is enough for us if we exhaust all the self tours in Rick's book. You might want to add the Frari Church to your list. The Canova and Titian tomb sculptures are remarkable.

If you go to Murano and Burano, that will eat up most of one day.

Maybe your kids would enjoy a treasure hunt. Let them head off by themselves.

https://www.fodors.com/community/europe/venice-for-teenagers-762890/

Steves' Guide Book for Venice has two or three self guided walks. We've done them and found them to be quite good. I believe he may have free audio guides that can be downloaded to expand on the walks.

Peter that's awesome. Any idea how long that treasure hunt takes?

CJean - I didn't realize Murano and Burano would take a day? Thought maybe a few hours?

When we do the islands we usually do Murano, Burano, and Torcello (which is the best, IMHO). It takes us about 6 hours taking a vaporetto from Fondamente Nove to start out about 9:30. We like to have lunch on Burano and we follow the Rick Steves guide for self-touring the islands. Be sure to take the vaporetto from Fondamente Nove because if you take it from San Marco/San Zaccaria it takes a lot longer as you go all the way around Venice.

You can find the vaporetto schedules here. Burano seems to be at least 40 minutes away, and that's from Fondmente Nove, so you'd need first to get there.

The treasure hunt would take several hours. It is a bit dated - no kid goes to an internet cafe to check facebook, as that is what a phone is for. The Maccas near the Piazza exists no more, which is a good thing. The bookshop on Salizada San Moise exists no more, and is now a Luis Vuiton outlet, which is a bad thing.

Don’t be afraid to let your kids wander around. Sure, they will get lost, but they can’t get too lost as they are on an island. Venice is the safest city in the world, as there is no traffic.

A good meeting point is the middle flagpole in the Piazza. All they need to do is follow the signs saying “per San Marco”.

Gerri - the free tours look great. Have you done any? Do they get heavily crowded in the summer months?

Also found this free walking tour group, rated very highly too on TA. Anyone have experiences with either the one Gerri mentioned or this one?

http://www.venicefreewalkingtour.com/

Tamara - We did the morning tour. It covers a more diverse area of the city, and we weren't willing to see St. Mark's on someone else's timeframe
Which is more or less included in the afternoon tour.

Have not been there in the summer months, only spring and fall, but the fact you have to reserve I think limits the # they take. There were only six in our group in October 2016.