Here are some recommended free books collections. remember you local library may have many more subscription services.
Online ebooks Collection
Excellent index to free ebooks maintained by Penn University. Highlights individual titles and largeebook. directories. Over 1 million titles currently listed. Covers all subject areas
DOAB Directory of Open access books great site allowing searching and downloading of recent free boks from major academic publishers such as ANU, Manchester university
World famous project with thousands of titles .Most are e-books published before the 20th century and are free because their copyrights have expired.
National Academies Press
was created by the National Academy of Sciences to publish the reports of the National Academies of Sciences, Engineering and Medicine. High quality academic and scientific
Smithsonian books online- art, architecture, cultural studies