another good book is lima-6 : a marine company commander in vietnam or something to that effect.

you also might want to read vietnam: the soldier's revolt ( http://www.isreview.org/issues/09/soldiers_revolt.shtml ) it got it's obvious biases (it was printed by international socialist review) but rasies some excellent points about the role that class played in the dynamics of units. one argument that seemed very interesting: the was army was top heavy with officers each of which needed a combat command to get their next promotion. the demand for postings was such that officers served 6 month tours while enlisted served a one year tour. the result was officers with very little time and a lot of pressure to make a name for themselves so they'd send the grunts out on very dangerous missions with little regard for casualties. the enlisted men's response was to frag officers they viewed as the most dangerous to their lives. any way it's a really good piece, lots of quotes, but just watch out for that bias.