The paperback should be available anywhere you like to buy books. Just ask for ISBN 978-1497316010. Online, you should find it at such places as Barnes & Noble, Amazon, Books•A•Million, and Powell Books. MSRP us$6.99 (proportionate UK & EUR pricing), though most retailers will take advantage of wholesale pricing to offer at various discounts so by all means, shop around!
EBook is available through our usual list of major retailers, though at this exactly moment Nook hasn’t caught up with everyone and put the book for sale, it’s still “processing”. us$1.99 with proportionate pricing in various other countries as offered by the different retailers (51 countries for Apple, about a dozen for Kindle, etc.)