Guarnere was one of the authors of a best-selling memoir about Easy Company, 506th PIR, 101st Airborne: Brothers in Battle, Best of Friends. Edward J. "Babe" Heffron, Guarnere's co-author, died 96 days ago (on 2 December 2013), also at the age of 90.
The exploits of Easy Company, 506th PIR were popularized by Stephen Ambrose's book Band of Brothers and the HBO miniseries made from it.
If you read, you should read Band of Brothers. If you don't read, watch the miniseries, then read the book. If it interests you, read Donald Burgett's Currahee! and its sequels as well. They are sanitized, as many stories of war are, but they are also powerful. I prefer Burgett's books to Ambrose, but that may be because I read Currahee! decades before Band of Brothers was written.
I went to Normandy in 2009. I went through my images (how I wish I'd taken the good camera gear!) and found these: