Keeping Faith: A Father-Son Story About Love and the United Sates Marine Corps by John and Frank Schaeffer
This is THE book that I wish somebody had handed me the day that JC went off to boot camp. Gritty and down to earth details of boot in the days just before 9/11. Format is letters from dad to son, letters from son to dad, son's thoughts and memories, dad's thoughts and memories. Despite the changes in narrative voice, the book hangs together and is a great read on its own even if you don't have a Marine in the family.
PS: Please, no political posts in comments. The fact of the matter is that I AM the mother of a United States Marine.