Don't know about books, but here's a couple of links
list of top snipers -
http://www.snipercentral.com/snipers.htm
Simo Häyhä, reportedly the top scoring sniper of WWII -
http://mosinnagant.net/finland/simohayha.asp
P.S. there is a memoirs of Sepp Allerberger published - he had a couple of hundred confirmed kills for the German's on the Eastern Front. Just search Amazon books for "sniper" and you'll see it, as well as Jack Coughlin's book (he's a US Marine sniper - wrote an autobiography entitled "Shooter").