For distance, what type of touring are you doing? Camping and hauling all your gear and food, Hoteling it, having someone carry all the gear in a car, or somewhere in between. The more gear you carry the less miles per day. Do you want to stop and take pictures and see the sights in every town? 50-75 mile average per day is usually what I have seen. Distance does not always decline per day.
For routing take a look at http://www.adventurecycling.org
Northern Tier maps, the Erie Canal Towpath in NY, and along Lake Ontario in NY. Also checkout Crazy guy on a bike's website
, there are many journals of biking trips, some with route details.
I use Delorme street atlas for my own routing, setting it for bicycle and then setting the distance option for 75 miles per day. I then can see where to look for overnight stops.
Last year I toured around lake Ontario, carring all my camping gear. 600 miles in 11 days. I had 2 days in a row of around 90 miles and had some days of 45 miles. the distance was set more by campground availability then anything else.
I live in Niagara Falls, NY and can help suggest directions closer to N.F., but I am leaving tomorrow for a 12 day 900+ mile tour around Lake Erie.
Good luck and happy touring.