Adii Pienaar, founder of WooThemes, has announced the pre-order availability of his upcoming book Designing Emotion on Amazon, which he is co-authoring with John O’Nolan, a WordPress developer and member of the WordPress UI team. The book is listed for pre-order at £15.29, and O’Nolan confirmed on Twitter that the book will be available digitally for the iPad, Kindle, and in ePub formats.

Pienaar recently published Rockstar Business, “a special collection of inspirational stories, thought-provoking reflections, and take-it-from-me advice.” O’Nolan has a collection of his published works on his site, and is also the Technical Editor for Smashing WordPress Themes, due out in 2011.

Designing Emotion is slated for a May 2011 release, according to Amazon. You can follow Pienaar and O’Nolan on Twitter @adii and @johnonolan, respectively.