The National Academies Press is making PDF versions of its books available for FREE.
You must sign up with an email address, but then you can download free PDFs of over 4,000 titles on science, technology, and health, and education from the NAP Web site. Such as:
Taking Science to School: Learning and Teaching Science in Grades K-8
The Future of Nursing: Leading Change, Advancing Health
Ensuring the Integrity, Accessibility, and Stewardship of Research Data in the Digital Age
Strengthening Forensic Science in the United States: A Path Forward
