To reach the hotel via Public Transportation 
from the Boston Train Station you would:

Take the Red line inbound to Central Square stop.
Follow Massachusetts Avenue 3 blocks 
(The Dunkin Donuts CVS Pharmacy should be to your right).
Take a right on Sidney Street (at the fire station);
hotel is on the corner of Sidney and Green Street.

From Logan Airport you would do the following:

Take the airport shuttle from your terminal to the Silverline.
Take the Silverline to South Station.
Take the Red line inbound to Central Square stop.
Follow Massachusetts Avenue 3 blocks 
(The Dunkin Donuts CVS Pharmacy should be to your right).
Take a right on Sidney Street (at the fire station);
hotel is on the corner of Sidney and Green Street.