Mae Sot is located about 130km east of Sukhothai not far from the Burmese border. The town has an interesting mix of people, Thai, Burmese, Hmong and Karen. Many Burmese traders cross the border each day to sell their goods in Mae Sot.
From Sukhothai take a bus to Tak and from there a minibus to Mae Sot. Total journey time is about 2½ hours.
Thai International have daily flights from Bangkok to Tak. The bus from Tak takes about 1½ hours to reach Mae Sot along a very picturesque route.
There are plenty of Songthaews for journeys around town or further afield. You may be able to hire a car and driver if you wish to go sight seeing, ask at your hotel.