After reading some of the negative comments in a few of the reviews, even in the so-called "positive" reviews - I just had to add my 2-cents: THEY'RE WRONG! This is nothing short of GREAT.
I'm not just speaking as a Kirby Devotee (which I am), or even a comic collector (also true). My exposure to Jack Kirby's groundbreaking 60s work at Marvel inspired me to become an artist and graphic designer. He was kind enough to respond personally to me when I was 14 and sent him a sample of my own comic work. I was lucky enough to meet Jack and Roz personally many years later in the mid-70s and spend part of an afternoon with him one-on-one. So I'm speaking from a deep familiarity with his work and some personal experience, as well as my professional background.
First, let's dispel the notion that KIRBY: KING OF COMICS is a biography. It isn't. There is no place in the book that calls it a "biography". It also isn't an art book with too much copy. This is a compendium, a celebration of Kirby's life and accomplishments, an overview with additional depth, an inside look from the people who knew him, worked with him, lived with him and loved him, with an attempt at balance and historical perspective that is often lacking in other biographical works about Kirby.
It's true that much of this material has been covered before, both in the shorter biographical works that have appeared and in the very excellent "Jack Kirby Collector". However, Mr. Evanier has done an excellent job of both organizing the information in an exciting and dynamic way, and adding details and perspective not available to other writers. Just the fact that he has had access to Roz Kirby and the Kirby offspring adds insight not previously seen. Not only that, but the "voice" Mr. Evanier uses is more chatty, more casual, more like Jack than any other book about Jack I've read. Despite what some reviewers have said, this does not come off as an uninvolved objective journalist. It sounds to me like a guy talking about a very dear friend without over-inflating the facts.
As far as those who think there's too much negativity and blame-laying, all I can say is lighten up! There were plenty of things that got under Kirby's skin, and he could be quite vocal about them. But he didn't dwell on those things for long, and neither does the book. The fact is, some bad things happened, and Jack was treated unfairly in a lot of ways. All of that is covered here, along with Jack's opinion about the situation, and quotes from others involved. Unfortunately, Kirby could be a little naive when it came to the business side of things, and his kind nature was easy to take advantage of by some of the unscrupulous folks in publishing. However, that is not the main focus of "Kirby".
What is the main focus are his accomplishments, and the book makes it clear (if there was ever any doubt), that Jack Kirby did more to create the look, feel, language and dynamism of comic books as they exist today than any other single person.
As for the art, I'm here to tell you that you ain't seen nothing of Kirby unless you're one of the fortunate few who can afford to buy an original comic page. Even the reproduction in TJKC - which is excellent - can't compare. Each and every piece of art is reproduced in full color, even the black and white pages. That may not make sense to those of you unfamiliar with printing and graphic reproduction techniques. But seeing both the penciled and inked pages AS THEY ACTUALLY LOOK IN PERSON is totally different than looking at a black and white reproduction. You can see all the nuances of Kirby's pencil lines, his shading, the un-erased (and sometimes even the erased) images behind the inking. The power and dynamic these pages illustrate are unmatched by anything else I've seen about Kirby's work. And yes, there are still some things that have never been seen before.
My recommendation: keep an open mind, buy the book, and read it as if Mark Evanier was sitting in your living room, telling you all about the guy who did more for comic boooks as an art form than anyone else.