First off, let me say that I am a great admirer of Isaac Newton. Einstein is who he is and deserves every accolade put upon him but, in my opinion, humankind has never produced a scientific genius as great as Newton. He understood the world in a way that has never been equaled before or since.
That being said, let me also say that this is a very good biography of Newton. It is brief so it is easily digestible by anyone. Still, what is lacks in depth it makes up for in coverage. We get glimpses of many parts of Newton's life, from his obsessive questioning and scientific investigation of the plague/fire years through his hiding-in-plain-sight years at Trinity through the renown of his London years as President of the Royal Society and Warden of the Mint.
Gleick also does not shy away from the less understandable parts of Newton's nature--his hypersensitivity to criticism, his theological struggles and his relentless alchemical investigations. Though, as this biography makes clear, even his ability to achieve his well-known and -respected triumphs in mathematics and physics really defy understanding. Let's face it, there is something about genius that is beyond any kind of clarity for those of us not touched by it.
Anyone interested in a quick look at an amazing man should read this book. I would also suggest taking the time to follow the many endnotes that Gleick has provided. Unlike many notes of this type, these are very readable and add to the text, though some probably could have been added right to the body of the text without much interruption of the flow. In any case, Gleick has written a fine book about a true genius.