Open Access (OA) journals are now found within almost any database or journal collection. There are also publisher sites that feature OA journals. See the attached list.
Open Access (OA) books have been a little slower coming than journals but they are now a standard feature of the research landscape. Most major publishers now publish OA books and feature them in their packages and on their web sites. See the attached list for some publishers’ sites that feature them.
Directory of Open Access Books (DOAB)
OAPEN (Open Access eBook platform based in Europe)
Project Muse Open Access Books (Note: Click Only content I have access to.)
Taylor & Francis Open Access eBooks