215 miles in a day and a half. you go dude!
The short way to manchester is up NY Rt 22 .What I would do is take a metro north (harlem line) to wassaic station that will knock off 80 miles and you won't have to ride through Busy Westchester and the Hills of Putnam county. The 12 mile section of rt 22 between Wassaic and Millerton is in pretty rough shape this year with a lot of broken pavement on the shoulder, instead take the Harlem Valley rail trail to Millerton. http://www.hvrt.org/
At Millerton get back on Rt 22 north for about 30 miles to interstate 90 .This section aint too bad it has a decent shoulder most of the way though there are are few stretches of rough pavement and a couple of pretty good hills. North of I-90 you will stay on RT 22, you will go over a hill after I-90 that is a bit twisty and doesn't have much of a shoulder, beyond that Rt22 is mostly smooth and wide the 50 miles to Cambridge NY where you will go east on NY Rt 313 16 miles ( beautful ride!) to Arlington VT , At Arlington you go north on RT 7a to Manchester which is about 10 miles.
As for maps you won't need much more than a good state roadmap . or download and print from google or mapquest