
In fact, there's nothing special to their guide apart from the fact that they don't affix the required L-bracket to the inside of the bottom book. Instead, they just bought sufficiently large brackets and figured that the limited visibility of the brackets wasn't that big of a deal; having seen the results, we'd be inclined to agree.

Either way you go, the floating bookshelf is a fun and attractive way to put your books on display.
Invisible Bookshelves [via Apartment Therapy]