Social Security Online (http://ssa.gov)
This official Social Security Administration website answers questions most commonly asked about Social Security, disability benefits, and Medicare. It includes formulas for calculating benefits, information on qualifying and applying for benefits, plus relevant forms. Use the online directory to find the nearest Social Security office. The website also has forms and publications to help you plan your retirement, check the status of your application and to apply for disability benefits.
Legal Information Institute http://www.law.cornell.edu/socsec/
Cornell University Law School posts a Social Security electronic library on the Internet. It includes the full text of Martin on Social Security, links to Social Security laws and regulations, recent developments, the Social Security Handbook, and much more.