I was impressed with this, the information was accessible and it was not heavy in the academic theory of comic books (like The System of Comics). The comic-style format is akin to that of Scott McCloud's Understanding Comics and makes it much more enjoyable to read, Eisner even used some of his own panels from various comic books to demonstrate the various techniques employed by comic book artists. I gave it four stars because I wish it would have been longer, it is definitely a book for beginners to be used a simple point of reference for terminology and examples. I would recommend getting this with Scott McCloud's book Understanding Comics.
Together with "Graphic Storytelling and Visual Narrative" this is simply a must-have for anyone who's interested in understanding comics as an art form, or writing his own graphic novel. There's such a great amount of essential information in these books, and each concept illustrated is masterfully exemplified by Will Eisner with snippets of his graphic novels and comics. This new edition also contains notes about new tools and techniques (such as Photoshop) and new media (webcomics).