Obama also raised the maximum credit for families with three or more children from 40% to 45% of a household's earnings (up to a maximum amount), and that rate is slated to go back to 40% in 2013. This decrease could amount to a loss of more than $600 for families with at least three children who had previously claimed this credit, said Williams.

4. American Opportunity Tax Credit

Introduced as part of Obama's stimulus plan, the American Opportunity Tax Credit aims to help lower-income families pay for college. It replaced the Hope Credit and allows qualifying families to claim up to $2,500 each year for four years.

Obama made the credit 40% refundable, meaning a family that qualifies for the full $2,500 can receive $1,000 of the credit in cash and the rest must be applied toward their tax liability. That refundable $1,000 is especially important for low-income families, since they often don't have big enough tax bills to apply a non-refundable credit. Often, the refundable amount is the only portion they receive.

But the American Opportunity Tax Credit is scheduled to disappear at the end of this year and revert back to the Hope Credit. At that point, the maximum credit will drop to $1,800. Also, families will only be able to claim the credit for two years and it will no longer be refundable.

"Because the Hope Credit is not at all refundable, that's potentially $1,000 dollars out of the pocket of a college student, and when you're trying to go to college, $1,000 is a lot of money," said Williams.