There are lots of maps of Lovecraft Country out there, (and, naturally, lots of maps of Massachusetts), but these are some of my favorites.
I lifted the first three images -- Arkham, Innsmouth, and Kingsport -- from Maps of Non-Existent Places. Call of Cthulhu players will already be familiar with the Arkham map.
"The Dreamworld of H.P. Lovecraft", (illustrated by Jack Gaughan and printed in Fantastic Swordsmen, 1967) is based on a geography by L. Sprague de Camp. "Arkham Circa 1930" is by none other than Gahan Wilson and appeared in the Summer 1970 edition of The Arkham Collector. These latter two maps are scanned from An Atlas of Fantasy, 1st Ballantine edition, ed. J.B. Post.