If children’s books aren’t your thing, the National Academies Press may be a better fit. NAP was created to publish the reports of the National Academy of Sciences, the National Academy of Engineering, the Institute of Medicine, and the National Research Council. They publish more than 200 books each year on a wide variety of topics in science, engineering, and medicine.

Through their Joseph Henry Press imprint, they also publish authoritative books on science, technology, and health for the science-interested general public. The topics addressed by their publications are varied, including everything from modern physics and frontiers of medicine to scientific biography and early childhood development.

While print versions of all of their publications are available online, they also offer PDF downloads of more than 3,000 books. After signing up for a free account, simply add the titles to your shopping cart, and it’ll give you options for different types of media. While the books on the site aren’t all available for free download, many of them are.

I’ve already downloaded two titles on educational technology, and I’m looking forward to finding more resources on this site.