Peter Hathaway Capstick's books on African hunting - Death in the Long Grass, Death in the Silent Places, The Last Ivory Hunter, etc.
Theodore Roosevelt's classic, African Game Trails
John Taylor's book Pondoro - Last of the Ivory Hunters
W.D.M. Bell's books Karamojo Safari, Wanderings of an Elephant Hunter, and Bell of Africa.
For science fiction, I'd recommend the Lensman and Skylark series of books by E.E. "Doc" Smith . . . written before WWII, the science may be a bit dated, but they're still a good read and not contaminated by today's political correctness.