Tax Relief for Long-Term Care Act of 2008 - Amends the Internal Revenue Code to allow a tax credit for long-term care insurance premiums and for care provided by a caregiver to a family member or dependent with long-term care needs who resides with such caregiver. Phases in a maximum credit amount of $3,000 between 2009 and 2013. Reduces such credit amount for a taxpayer whose adjusted gross income exceeds $75,000 ($150,000 in the case of a joint return).