Cry of the Kalahari by Mark and Delia Owens. A couple of young American researchers set up camp in the remote Central Kalahari in the 1970s and spent seven years studying brown hyenas and lions. The writing is vivid and the Kalahari comes alive -- the heat, the isolation, the animals. Essential reading for anyone heading into the desert.
The No. 1 Ladies' Detective Agency by Alexander McCall Smith. This gentle, warm series set in Gaborone follows Precious Ramotswe, Botswana's first female private detective. The mysteries are slight but the books paint a lovely picture of everyday Batswana life -- the culture, the values, the landscape. Read the first one before your trip and you will arrive with a fondness for the country.
Serowe: Village of the Rain Wind by Bessie Head. Head was a South African writer who settled in Serowe and wrote about rural Batswana life with deep empathy. This oral history of Serowe, told through the voices of its residents, is a unique window into traditional village life and the changes of the twentieth century.
An African Love Story by Daphne Sheldrick. While primarily set in Kenya, Sheldrick's memoir of a life spent with African wildlife resonates strongly with the conservation ethic that defines modern Botswana. Good background reading for understanding why the country protects its wild places so fiercely.