Using Bing, you can find open directories full of free electronic books. Search and ye shall find.
Electronic books (or ebooks) are hidden all over the Internet in open directories. If you just know how to search, you can find numerous resources which provide free ebooks.
This search will look for open directories that contain common ebook formats and contains a word or two for selecting ebooks:
Bing: intitle:”index of” contains:(pdf chm zip doc) “last modified” ebook
This search will look for open directories that contain common ebook formats and contain a directories named “book”:
Bing: intitle:”index of” contains:(pdf chm zip doc) “last modified” “/book”
By adding titles or authors, you can focus your search even more. The following seach specifies the author “O’Reilly.”
Bing: intitle:”index of” contains:(pdf chm zip doc) “last modified” “O’Reilly”