This week's book giveaways are in the iOS and Features new in Java 8 forums. We're giving away four copies each of Barcodes with iOS: Bringing together the digital and physical worlds and Core Java for the Impatient and have the authors on-line! See this thread and this one for details.
The other jQuery books focus on using the built-in featues of jQuery - selecting elements, traversing the DOM, manipulating elements and attributes, event handling, and ajax - and may have only one chapter or section on writing jQuery plugins. This book looks only at how to extend jQuery with plugins - from custom selectors, to collection plugins, function plugins, jQuery UI widgets, custom events, animation, and ajax processing. It assumes that you are familiar with jQuery and are looking to extend your usage of it.