Given my nick, I believe I am qualified to give an opinion on this... :-)
There is a lot to do in Toronto, I do mean a LOT.
The first thing you need to know is that Downtown Toronto is very very very safe. A lot of tourists come here and stay in the suburbs thinking it is safer... in fact the opposite is true here. I strongly recommend that you stay in the downtown core so you can fully enjoy the city.
If you prefer to stay further out, you can leave the car behind and take the GO Train (
www.gotransit.com), or take the subway/streetcars
http://www.city.toronto.on.ca/ttc/. These have day passes that you can buy for unlimited use. The transit here is great and is easy to navigate.
Check out
www.toronto.com and
www.nowtoronto.com . These sites have listings of activities big and small on a daily basis.
Toronto has a theater district similar to New York - if you like that kind of thing there's lots of it here. Try
www.mirvish.com for some ideas... there are others as well.
If you are into clubbing til the wee hours, check out the entertainment district. Everything from Deep House and PsyTrance to Country and Western.
If you're into culture, museums, etc check out this link.
http://citypass.com/city/toronto.html there's a deal on a citypass that gets you into several attractions for one price.
If you like to try varied foods, Toronto has lots. Because Toronto is very very multicultural there are tons of authentic ethnic restaurants here - everything from Hungarian to South American.
The standard tourist spots are (no particular order):
1. CN Tower
2. Spadina Avenue - Chinatown
3. Yonge Street (longest street in the world)
4. Center Island (nice boat ride out to the islands from downtown)
5. King Street
6. Royal Ontario Museum
7. Art Gallery of Ontario
8. Casa Loma (An actual Castle in the city)
If you're here the first week of August there is Caribana... the largest celebration of West Indian culture in the world. It is INSANE! Huge street party and parade.
There's also some sort of deal here where you can get a bundled price on the hotel and a show. Check the web for details.
If you need any assistance planning, just let me know and I'll try to hook you up.
Best Regards!