I have been reading David Powers books for years and he is one author that I trust with communicating knowledge in a plain down-to-earth approach.
David is always ahead of the curve when you want to learn new technologies. This book is one of the first books that is being published regarding Adobe CS5.5. While at first glance you may think that the size of the book is limited to the amount of information that can be covered. However, many books are more "fluff than stuff." Not so with this book, every page is packed with useful information that can propel you ahead of your competition on new and emerging technologies (i.e., jQuery Mobile, HTML5, CSS3, PhoneGap, etc.).
The book is divided into three sections. The first section gives a summary of HTML5 and CSS3 with techniques on how to make them compatible with their older counter-parts (XHTML and CSS2).
The second section highlights the different between graceful degradation and progressive enhancement. While many designers and developers use these terms interchangeable, there is a subtle difference between the two. Graceful degradation is based on the premise that if a feature is not supported by a particular browser, a fallback solution will prevent the design from failing completely. With Progressive Enhancement; however, a website is designed to work on all current browsers from the outset and additional "enhancements" are "progressively" added based on browser capabilities or when a user upgrade to a newer browser. New enhancements to media queries are also discussed. Media queries allow designers to style a page based on the type of media a viewer in currently using, typically, a computer, a tablet or a smartphone. A brief discussion of how to make a web site available offline is also included in this section.