There are a number sites that provide free online access to books related to engineering. The selection of engineering and technology books is limited compared to the number of titles available in other disciples and those available for purchase. Here are some of them.
Directory of Open Access Books The primary aim of DOAB is to increase discoverability of Open Access books. Academic publishers are invited to provide metadata of their Open Access books to DOAB. Metadata will be harvestable in order to maximize dissemination, visibility and impact. Aggregators can integrate the records in their commercial services and libraries can integrate the directory into their online catalogues, helping scholars and students to discover the books. The directory is open to all publishers who publish academic, peer reviewed books in Open Access and should contain as many books as possible, provided that these publications are in Open Access and meet academic standards.
Project Gutenberg is a library of over 60,000 free eBooks. Choose among free epub and Kindle eBooks, download them or read them online. You will find the world's great literature here, with focus on older works for which U.S. copyright has expired. Thousands of volunteers digitized and diligently proofread the eBooks, for enjoyment and education. Everything from Project Gutenberg is gratis, libre, and completely without cost to readers. If you find Project Gutenberg useful, please consider a small donation to help Project Gutenberg digitize more books, maintain our online presence, and improve Project Gutenberg programs and offerings. It provides for Basic Search by keyword or field, also "Latest" and "Random" eBooks, Advanced search with all search fields and categories and the ability to Browse Catalog by author, title, subject, language and categories; full-text searching. Searching the broad subject Engineering is a good way to get started.
The National Academies Press The National Academies Press (NAP) publishes the reports of the National Academies of Sciences, Engineering, and Medicine. The NAP publishes more than 200 books a year on a wide range of topics in science, engineering, and medicine, providing authoritative, independently-researched information on important matters in science and health policy. They offer more than 8,500 titles in PDF format. Almost all of these PDFs can be downloaded for free by the chapter or the entire book.* See About PDFs for more information on accessing our digital content.
Open Stax Textbooks OpenStax is a nonprofit educational initiative based at Rice University, and it's our mission to give every student the tools they need to be successful in the classroom.
The Open Textbook Library Open textbooks are textbooks that have been funded, published, and licensed to be freely used, adapted, and distributed. These books have been reviewed by faculty from a variety of colleges and universities to assess their quality. These books can be downloaded for no cost, or printed at low cost. All textbooks are either used at multiple higher education institutions; or affiliated with an institution, scholarly society, or professional organization. The library currently includes 706 textbooks, with more being added all the time. Two relevant subjects for engineering are Computer Science and Information Systems Textbooks and Engineering. The Open Textbook Library is supported by the Center for Open Education and the Open Textbook Network.