If you're looking to hit some clubs in Toronto, Richmond Street between John and University has tons. For some dinner and your older bar crowd, King Street between John and University will give you a large variety. If your looking to hang with the university type crowd, check out The Annex (around Bloor and Bathurst) or the Spadina/St George and Bloor area. For some higher end bars, Yorkville is where you want to be.
The best hill in Ontario would be Blue Mountain. However, in comparison to places such as Whistler, Banff and Mont Tremblant, Blue Mountain is tiny.
If you clarify where you're going to be in Ontario, I can help you out a little more.