For the most up-to-date listing of open-access journals, the Directory of Open Access Journals (DOAJ) site provides a directory of thousands of open-access journals.
For the most up-to-date listing of open-access books, the Directory of Open Access Books site provides a directory of thousands of open-access books.
The U.S. National Science Foundation's Public Access Initiative ensures the outputs of NSF-funded scientific research are made publicly available to the greatest extent, with the fewest constraints possible and consistent with law.
Visit NSF's public access initiative page for more information.