If you are looking for some historical reading material and something sniper related, A Rifleman Goes to War by Herbert W. McBride ,his book is considered one of the all-time classics on the art of military sniping, and is still on the required reading list of the U.S. Marine Corps Sniper School.
McBride is a facinating read not only for the sniping but his life itself. He was an American who gave up his commision in the National Guard to join the Canadian Army in 1915, went in as an officer but worked his way down to private.
The other book he wrote on his WW1 experience was The Emma Gees which focus on his experience as a machine gunner