I lived and worked in MI for part of 2009. I moved to PA, but have not worked. Do I still file state taxes in PA or just MI?

If you did not have any income while present in PA, you do not file PA tax return. You will file MI tax return. Your U.S. Tax Return: Working or Living in Two or More states (http://taxipay.blogspot.com/2008/06/working-in-two-or-more-states.html)

File in MI as a part-year resident, so tyat you pay tax to MI on income you earned while you were living there. You MAY have to file a PA part-year resident form as well, even though you had no income when living in PA, depending on your total income for the year - look over the instructions for the PA part-year resident return to see what the filing requirements are. However, even though you may have to file a return with PA, you shouldn't owe them any taxes (assuming your income while a PA resident is $0). Starting with tax year 2010 you file only as a full-year resident of PA.

You are going to have to file a dual tax return and your taxes for both states are determined by how long you have lived there during the tax year definitely have someone like jackson hewitt file your taxes we had to do that this year for two different states