If your hotel is in the center of Sendai, it will be within walking distance from Sendai Station. The Roynet Hotel, for instance, is about a 8-minute walk. But if you have much luggage you could take a taxi, at a cost of about 600 yen. The Washington Hotel I and II are about a 15-minute walk, and you will need a taxi to get there. This will cost about 1,000 yen.
A map of central Sendai as well as some useful expressions written in Japanese to show the taxi driver are enclosed.