I highly recommend “My Secret War” Richard S. Drury’s story of flying Skyraiders over the Ho Chi Minh trail.
Also “Ravens” about FAC pilots in Laos. “Thud Ridge” on the subject of flying F-105 bombers over North Vietnam
Two other excellent books in the same genre are:
"Flying Through Midnight: A Pilot's Dramatic Story of His Secret Missions Over Laos During the Vietnam War" - flying C-123s at night, including an absolutely hair-raising description of a night emergency landing at the "nonexistent" CIA base at Long Tieng.
"Low Level Hell"- an account of Loach operations in Vietnam.