Less-traveled, easy bike trails?

[rjkp.livejournal.com]

 Hi.  I'm looking for recommendations for easy, quiet/empty bike trails anywhere within 45 minutes of Boston.  I'm kind of rusty, and I just want a nice place to practice riding my cheap road bike in peace.  The Minuteman trail is tough for me, because I'm out of practice and I spook easily, and the bike/rollerblade/jogger/stroller traffic is too much for me!

Any ideas would be appreciated...thanks!