what states. most likely you can only do it once you get to the states. I assume that you answered that you lived in state x at the end of the year and state y from the beginning of the year to some date before 12/31. then under each sate there should be a form it might be labeled NR or PY which you should get to once you finish the federal and start on the states. you should see the states listed and see that each is marked part-year resident. if a state does not have a personal income tax you won't see it.
