Here is a word from the Goodfellas at the IRS:
IRS Tax Tip 2013-24
Some people must pay taxes on their Social Security benefits. If you get Social Security, you should receive a Form SSA-1099, Social Security Benefit Statement, by early February. The form shows the amount of benefits you received in 2012.
Here are five tips from the IRS to help you determine if your benefits are taxable: