1.At CHMPDF (www.chmpdf.com/archives/ebooks) you can find a collection of general interest and technical e-books.
2.At FreeComputerBooks.com you can find free computer, mathematics, technical books and lecture notes, etc.
3.At FreeTechBooks.com you will find free online computer science and programming books, lecture notes and textbooks.
4.Online Computer Books at www.onlinecomputerbooks.com lets you download free computer books, free e-books and read books online.
5.At Realtime Publishers (www.realtimepublishers.com) you will find free IT e-books by world’s best authors.
6.If you’re interested in technology, then visit site www.freetechbooks.com. It’s a site that links to to free computer science and engineering books.
7.Old technical books from the “vacuum tube age” can be found online at www.pmillett.com.