Health Communication, Health Literacy and e-Health Collection of resources for understanding patients' use of electronic health information and improving health literacy. Published by the U.S. Department of Health and Human Services, Office of Disease Prevention and Health Promotion.
National Assessment of Adult Literacy (NAAL): Health Literacy Comprehensive report of English literacy among American adults age 16 and older. Publications and data files are also available. Published by the National Center for Education Statistics.
PlainLanguage.gov Comprehensive resource from the Federal Government that includes background on health literacy as well as guidelines and other resources to aid in producing materials readers can understand.