SSI
The Social Security Administration has a
SSI Child Disability Starter Kit
(for children under age 18). The toll free number for the main Social Security office is 1-800-772-1213.
The Social Security and Disability Resource Center
http://www.ssdrc.com/
An informational website written by a former claims examiner for the social security administration, and addresses many questions that people often have about the application process, but have trouble finding clear answers to.