I wonder how one can be surprised that the book is English. You can read it in the product (see language -> English):
Product Information
* Hardcover: 192 pages * Publisher: Collins Design (3 November 2009) * Language: English * ISBN-10: 0061864153 * ISBN-13: 978-0061864155 * Size and / or Weight: 29.4 x 24.6 x 2.8 cm