My only income in 2008 was $26000 in SS Checks. Although I live with my wife
She chose to file separately. Will I have to pay tax on this $26000 Income?
There is no other income or interest income.

PUZZELLED??

If that SSI was the only source of income into your family, then no. However if your wife makes income, then it can be taxed. Contact your local library and see when the V.I.T.A. team will be there. They offer free tax help to anyone who asks for it, and they can help you find the best way to file. Good luck!

Page 27 of this IRS publication (1040 instructions) is a worksheet for determination of taxable SS benefits. For other than form 1040 you may need to do further research;
http://www.irs.gov/pub/irs-pdf/i1040gi.pdf