Based on your experience and timeframe I'd suggest crossing New York with the Erie Canal to avoid the Appalachian Mountains.
I can't offer much help in getting from Lake Michigan to Lake Erie.
http://www.great-lakes.net/tourism/circletour/michigan/
http://www.great-lakes.net/tourism/circletour/erie/
http://ptny.org/guidebook/erieguide.shtml
http://ptny.org/guidebook/hudsonguide.shtml