Metro - The metro (subway) is fast and speedy, use it to go from downtown to the Olympic Park or Ile Sainte Helene. Purchase a 1 or 3 day ticket, good for unlimited rides on the metro and buses. Tip: Ticket is also good for 747 bus that goes to the airport.
Bus 515 runs in loops around Vieux Montreal and the waterfront from downtown. Ride the loop to get oriented and go from one end of the old port to the other.
Fun food
The farmers markets in Montreal are the best. One parent writes, "We let our kids have a little money when we go and they spend a long time before making their decisions. Sometimes its honey sticks, a lump of maple sugar candy or basket of summer strawberries." You'll find locally made cheese, cookies and pastries, fruits, bread, quiche, waffles, and ethnic specialties. Try the maple cornets, tiny little cones with tire (maple taffy) and sucre (maple butter). Check out Marche Jean Talon or the Atwater Market, open year round.
Bagels - Bagels are a local Montreal specialty. It's fun to watch bagels being made - big slices of dough are whacked off, shaped into circles, boiled in sweetened water, then cooked in wood-burning ovens. Bagels are typically plain, sesame or poppy seed, but you'll also find blueberry, chocolate and granola (muesli). See bagels being made at St-Viateur Bagel.
Poutine - Poutine is French fries, with brown gravy and melted cheese on top - fun snack for kids. Also, comes with hot dogs and chicken, and variety of different sauces.
Cafes - When the weather turns bad, stop into a cafe for hot chocolate (totally delicious), croissants and locally-made bagels.
Here's our own Travel for Kids hand-picked list of family hotels, all styles and price ranges, convenient to fun things to do with kids in Montreal: