DOAB is a community-driven discovery service that indexes and provides access to scholarly, peer-reviewed open-access books and helps users to find trusted open-access book publishers. All DOAB services are free of charge and all data is freely available. 

E-Books Directory is a daily growing list of links to freely accessible ebooks, documents and lecture notes found all over the internet. You can submit your own ebooks, or add other resources you come across. Look below for the main directory of categories.