Ariel-
I usually go to Montreal in the summer--this year I took the trip to Disney instead. On the list of things worth seeing (in no particular order):
a) St Joseph's Oratory--beautiful basilica--breathtaking views of the city (lots of steps, however)
b) Old Montreal--take a walk down by the water to the old city--and make sure you go in the evening when there's lots of street entertainers! Check out Plaza St-Jacques at night!
c)Biodome de Montreal--a zoo (they have live webcams, too--I loved the penguins) in a stadium used for the Olympics in '76
d) Botanical Gardens (across the street from Olympic Park)--absolutely amazing! Plan on spending several hours. Nice place to eat outside!
e) Rue Ste-Catherine--fast pasted street--lots of pople, lots of shopping. Eat outside and watch the people!
f) Rue Ste Denis--more shopping, but small boutiques and such
g) Ile de Notre Dame--park on the small island downtown
h)Bonsecours Market--used to be open market--landmark
i) nightlife on Crescent St
j) the underground city
k)Le Saint-Sulpice--bar with outdoor terrance, three stories--my favorite hangout. Spent more nights there than I can count! Very friendly service--go around 10 to snag a table and wait for it to fill up!
l) Mont Royal/parc-de Mont Royal-- great views of the city
m)Olympic Park
Note that eating is big event in Montreal--take your time! Bars are open until I think 4 am--and the night doesn't get started until 11 or 12 at night... And put aside $10CDN to pay the airport tax on leaving Dorval if you're flying. No one escapes without paying it. You can also charge it.
Send me a PM if you have more questions. I had friends from Montreal show me the ropes, so there may be some obvious things left out here in favor of things I found more exciting. Have fun!