NIST: Computer Security Resource Center (CSRC): http://csrc.nist.gov/
NIST: National Vulnerability Database (NVD): http://nvd.nist.gov/
Guide to NIST Information Security Documents: http://csrc.nist.gov/publications/CSD_DocsGuide.pdf
Department of Health and Human Services (DHHS), Centers for Medicare and Medicaid Services (CMS), HIPAA Resources: http://www.cms.hhs.gov/hipaa/hipaa2
Workgroup for Electronic Data Interchange (WEDI): http://www.wedi.org