If you are not accustomed to reading books concerning military history and/or are not familiar with this stage of World War II, I'd highly recommend that you watch the BBC/HBO series first. It's very accurate to what is written in the book with good character acting to the main guys involved in Easy Company, 506th PIR of the 101st Airborne.
The book is well written, with Ambrose setting out the events of each day/engagement/battle/incident, and then using quotes and excerpts from other books and memoirs to illustrate how it was for the actual men in those incidents. A lot of the quotes are directly from interviews the author had with the various enlisted men and officers who took part in D-Day and beyond. It is stated towards the end of the book that Ambrose was in constant contact with the veterans of Easy Company and showed them drafts of the book to make comments and corrections on. So this book is pretty much the definitive history of Easy Company's part in World War II, from the birth of the company to through D-Day and then duties of Occupation in Germany etc.
The book loses one star for these down points:
It IS hard not to be in awe of what Easy Company and all the 101st achieved, but in one or two places, objectivity would have been prefered to all out adoration. If you are a Brit and have any soft spot for the achievements of the British contribution to the Allied advance in 1944, be prepared for the author to spurt out the odd punch to British forces. In a lot of places he seems to suggest that the British were blind, ignorant, and badly trained buffoons; and takes one or two unprofessional incidents to act as a general overview of British standards.
The minor sour grapes accepted, this is still a fantastic book, and there will be something on every page that will make you smile, or shock, or bring you close to tears. Every World War II enthusiast and history fan should read this book!