As with most Norton Critical Editions, this is an excellent resource - a dense yet readable selection of classic and lesser-known texts comprising a broad and fairly deep overview of Newton's work and its meaning.
Students and scholars will find here an enormous wealth of material, including extensive selections from Newton's major works and correspondence, as well as contemporary responses from his rivals such as Berkeley and Leibniz; most of the "core" Newtonian texts and correspondence are well-represented. There is insightful commentary from leading scholars such as Alexandre Koyre, David Gregory, Alfred North Whitehead, Albert Einstein, and many others; the editors' short introductory essays are also of value. There is a very useful Glossary of Newton's technical terminology, which is not always easily understood. Many of Newton's illustrations are reproduced, which is very important in understanding both the content and flavor of his reasoning, but the more abstruse mathematics is usually avoided. All together, this a valuable and accessible one-stop reference collection.
There are some points for criticism. There is very little biographical information, nor discussion of the intellectual and scientific context in which Newton worked, which is vital to understanding many of these texts. The collection is organized thematically, which may be useful in one way but also means that selections from individual works are scattered throughout the volume in small chunks. The Glossary could be more detailed. And it is frustrating that only Newton's side of his significant correspondence with such figures as Cotes and Oldenburg is given - it would be helpful to have included the corresponding letters from these writers as well, or at least more systematic selections from them. Necessarily, few texts are given in their entirety, which is an unavoidable hindrance. Necessarily also, each of the individual thematic sections is disappointingly sketchy. Given the size of the Newtonian corpus, and the breadth of his intellectual interests, these latter two facts are the inevitable result of attempting a reasonable breadth of coverage of his work in a single volume, and cannot be held against the work or its editors. This does mean, however, that the volume will serve most scholars as a reference to more complete editions rather than as a primary source. For the for the intelligent general reader who has enjoyed popularized commentaries such as those of Cohen or Stephen Hawking, the volume will serve well as the next step in deepening their knowledge and understanding.
All in all, this book is a vital component of the collection of anyone interested in understanding Isaac Newton's work in real detail.