May want to check out this site (if you didn't already know about it)
http://www.waterfronttrail.org/index.html

There's also going to be a new train service that will go from Toronto to St. Catharines
http://www.biketrain.ca/
What you may want to consider is taking the train here, then going along this route:
http://www.regional.niagara.on.ca/go...r/default.aspx Very nice route, though all I've done is Port Weller to Welland.
Here are pictures I took when I last took the trail (June 21, 06) http://picasaweb.google.co.uk/ryanz4...eRideToWelland
Just beware of riding in Niagara Falls. Tourists generally won't pay any attention to you. Same problem here in St. Catharines also, just not as bad as the Falls.