Your early retirement ss benefits will be treated just like your disability benefits.
Your regular income plus 50% of your ss benefits (early retirement OR disability) will determine if any or none of your ss is taxable. You may reduce the total by 25000 (32000 if married filing jointly ) if you are single. The amount is -0- if you use Married Filing Seperate filing status.
http://www.irs.gov/pub/irs-pdf/i1040gi.pdf This worksheet and the following worksheets will help you compute any taxable portion.
You may wish to review amending your 2007 and 2008 returns to see if benefits paid to you in 2009 for the prior years will be better taxed in those years or remain on your 2009 return.