I've read an Army at Dawn years ago and liked it. I've had the next book, the day of battle sitting in my shelf fir years and now that I'm considering reading it I want to know if it's a credible series at all. Is Rick Atkinson respected?
It is a very credible series, in fact it's one of my main go to books when people ask for recommendations on that topic (American operations in the ETO and MTO during WWII). He's not a historian by trade (he's a former journalist with the Washington Post) which some people might take issue with, but Atkinson did a fantastic job with his research, and his narrative writing is top notch.
An Army at Dawn also won the Pulitzer Prize for history in 2003, which should give you an indication of how the book and the rest of the Liberation trilogy was received by the general public and historians alike.