The way these floating bookshelves work is by using a bottom hardcover book to conceal the shelves. The end result looks like the stacked books are floating in midair.
You can buy an Umbra Concealed Bookshelf, which was invented by Pratt Institute student Miron Lior. They're easy to install, and you don't have to ruin your books.
Or you can make your own as a DIY project, which actually isn't as hard as it sounds.
Basically, you need one or two metal wall brackets. Screw them into your wall so that they're level with each other. Also make sure they're close enough together to hold the book you want to put at the bottom of the shelf.
eHow recommends spacing them four-and-a-half inches apart, like so:
Now you just have to pick a hardcover book to put on top of it. eHow suggests cutting two slits in the book jacket before fitting the book back into place — you can see the further instructions here.
If you want to avoid cutting holes in your book jacket, Caitlyn at Instructables recommends another tweak — you can velcro the back flap to the book's pages. That way, the bracket sits between the internal pages of the book and the back cover. The book is velcroed together so that the back flap doesn't hang down, and so that the bracket is concealed.
Gujarat Police Academy Road, , Karaigam, Nana Chiloda, , S.P. Ring Road , Gandhinagar , Gandhinagar - 382355 , Gujarat , India
5E- Royal Orchid , 183, SK Deb Rd , West Bengal , Lake Town , Kolkata - 700048 , West Bengal , India
526-527, Vishala Supreme , S.P. Ring Road , Opp. Torrent Power , Nikol , Ahmedabad - 382350 , Gujarat , India
44, Neptune Estate , Sardar Patel Ring Road , Behind Royal Hotel , Odhav , Ahmedabad - 382415 , Gujarat , India
Plot No.8, Shivshakti Estate, , Nana Chiloda, S.P Ring Road Circle, , Nr. Shyam Palace Hotel, , Gandhinagar , Ahmedabad - 382330 , Gujarat , India
409, 4th Floor, "Central by Sangath IPL" , Next to PVR Cinema , Near Lake & Garden , Motera , Ahmedabad - 38005 , Gujarat , India
2nd Floor, 304/284 , Bbmp Road, C-7 , Lakshmi Complex , Yelahanka Old Town , Bangalore Urban - 560064 , Karnataka , India
Plot no. 116 , Rudra Industrial Park, , - , - , Ahmedabad - 382433 , Gujarat , India
562A , Romford Rd , Stratford City , London Borough of Newham , City of London - E12 , Greater London , United Kingdom
106 Apple Street, , Suite 113 , - , Tinton Falls , Monmouth - 07724 , New Jersey , United States of America
Door old No. 19 / New, 41, , Tirumurthy Nagar , Nungambakkam High Road , Nungambakkam , Chennai - 600034 , Tamil Nadu , India
Plot No. 462, , Road No. 12 , Kathwada G.I.D.C. , Odhav , Ahmedabad - 382430 , Gujarat , India