Here are the List of Some sites from where you can get free Books:
- Gutenberg Project Top 100 – Popular books from the oldest producer of free ebooks on the Internet
- BookMooch – Community for exchanging used books
- ebookSpyder – Specializes in technical books ranging anywhere from C# to AJAX
- Google Book Search – Read the classics online
- Word Public Library – 400,000 PDF ebooks for download
- Free Tech Books – Free computer science and engineering books (+ lecture notes)
- Bookins – Swap real books with other readers
- WellToldTales – Free short story podcasts (like audiobooks, but shorter)
- Wowio – Public domain, free legitimate copyrighted materials & one of the only with a selection of Comic Books
- BizBooktalk – Free book giveaway contests on Fridays
- MoochMuch – Organize your book lending with your friends
- CHMPDF – A collection of general interest and technical ebooks
- Realtime Publishers – free IT eBooks by many of the world’s best authors
- FrugalReader – Trade Books for free
- TitleTrader – Swap books, movies, and music
- ZunaFish – Trade your old media and books items for new titles you’d rather have
- SwapSimple – Swap your used books here
- SwapThing – Community of users who swap items including books
- BookCart – Internet paperback exchange
- SF-Books – Exchange Sci-Fi Books here

We recommend! 



Very good list. You missed bookcrossing.com where people exchange books freely.
Great work.
I would like to add 1 more useful site to that list.
http://www.flazx.com— Computer and IT learning centre
That was a good compilation. Stumbled.
Thanks Nirmal
and it is my best website http://www.ebooksdownloadfree.com