Amazon.com have created pre-order pages for the Kingdom Hearts 3D [Dream Drop Distance] guidebook by BradyGames. You can see the North American page here, the UK page here, and the Germany page here. According to these pre-order pages, European countries will see the book released on July 12, 2012, and North America will receive the book on July 31, 2012. The full title of the book is Kingdom Hearts 3D: Dream Drop Distance Signature Series Guide. Thanks to JayC from KH13 for the find.

Update 1: GameStop have created a page for the guidebook, which is priced at US$19.99, and releases on July 31, 2012 in North America. This page also reveals the cover of the book, which can be seen below. Thanks to Terranort9406 from KH13 for the find.

Update 2: The European release date of the book has changed to July 27, 2012, shown on the Amazon pages for the UK and Germany. Thanks to chrisn1211 for the tip.