Guptill wrote this book about America's favorite illustrator at the height of his career, back in 1946. His career had another twenty years to go at that point, including at least 70 more of his famous Post covers. This book is a snapshot and retrospective of his work up to that time.
You won't find the usual biographic data here: parents, childhood, and the rest. Instead, this praises the illustrator who had captured the country fondness and respect by capturing its image - the image that America wanted to have of itself. Small wonder the country wanted to know more about the man who knew so much about them, or at least about their hopes and dreams.
Rockwell adopted a chatty, conversational tone with the author. He described every aspect of his working process, including the professional, conceptual, and painstaking technical steps he went through. The book is profusely illustrated with his preliminary sketches and drawings, as well as some photos of biographical interest. A few paintings appear in color, but the large majority are black and white, often of indeterminate contrast or focus. Remember the purpose of this book, though. This isn't a gallery of his work; instead, the reproductions serve to illustrate his career. Most appear in only enough detail to remind the familiar reader about the general structure of any given piece.
Decide what you want - a collection of Rockwell's idealized images, or a look at the man himself. If you want just the pictures, this might disappoint you. If you want an introduction to Rockwell as person and artist, you'll find a lot to like.