I now reside in West Virginia, but work in Ohio and lived there until September of 2008. I still work in Ohio. I am trying to do my taxes online, and realized that I never had my employer switch my address, meaning that I have been paying Ohio taxes, and have not paid any to state of West Virginia. Do I owe extra money to WV even though they were paid to Ohio? I'm not sure what to do next. I don't want to end up in trouble because of a dumb mistake on my part. Thanks for any advice

You need to first complete a return for Ohio as a part-year resident - reporting all your income for the year, and prorating that amount by any income you may have after you moved to WV that was not from Ohio sources (such as interest, dividends, capital gains etc that you received after you left Ohio) - you do that calculation on Schedule D of the Ohio Form IT 1040.

Then complete a WV tax return as a part-year resident. You will have to report all income again, then multiply by the fraction of time you lived in WV, then take a credit for taxes paid to other jurisdictions (Ohio) while living in WV - you do this on Schedule A and E of WV's IT-140. You may find that you owe some tax to WV, but unless you have significant sources of income other than your Ohio wages I doubt it will be much, if anything.

Be sure to update your address with your employer.

If you are present in a state, then any income earned during this period, must be reported to the state.

To your resident state, you must report your worldwide income for the residency period.
Read: 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)