I know of 3 off the top of my head: Edelweiss Mont Sainte Marie
I believe Camp Fortune is the nearest. I know Mont Sainte Marie is the biggest and the furthest from Ottawa. It used to be owned by Intrawest -- the owners of Whistler/Blackcomb, Tremblant, Stratton and many others -- but was sold in the last 2 years or so to (I believe) the Camp Fortune owners.
This is all based on my limited experience in the Ottawa area as well as on the discussions with a few friends I have in Ottawa.
Your best bet would be to contact a ski/snowboard club in Ottawa. A friend of mine had joined a snowboard club, but I don`t know the name of it. He told me that there also busses that will take you to the resorts.
To find a ski/snowboard club in Ottawa, you should probably start with a search engine (just had to state the obvious

and then contact the Ontario or Ottawa Ski/Snowboard federation.
I hope all that helps ! `later...