National Institute of General Medical Sciences
This booklet from the National Institutes of Health’s National Institute of General Medical Sciences explains the role of genes in health and disease, the basics of DNA and its molecular cousin RNA, and new directions in genetic research. It is available in e-pub (http://publications.nigms.nih.gov/epubs/TheNewGenetics.epub) and PDF (http://publications.nigms.nih.gov/thenewgenetics/thenewgenetics.pdf) formats.
Read this work at the World Public Library (library card needed).