Kosovo has a small but worthwhile reading list — part history, part memoir, part literary fiction.
Kosovo: A Short History by Noel Malcolm (1998) is the essential background text. Densely researched and determinedly fair, it traces Kosovo's history from antiquity through the 1990s and challenges many of the nationalist myths on both sides. Malcolm's broader Balkans histories (Bosnia: A Short History) are similarly rigorous and similarly essential.
Kosovo: What Everyone Needs to Know by Tim Judah (2008) is the more accessible companion — a Q&A format covering the political situation at the time of independence, written by a journalist who covered the region throughout the 1990s. Short and clear.
Three Elegies for Kosovo by Ismail Kadare is the great Albanian writer's poetic meditation on the Battle of Kosovo Polje (1389), the foundational trauma of both Albanian and Serbian national identity. Not a history book but a literary one — three narratives woven around the battle. Kadare is the most important literary figure Kosovo and Albania have produced; almost anything he wrote is worth reading.
Travels in Blood and Honey: Becoming a Beekeeper in Kosovo by Elizabeth Gowing (2011) is a memoir by a British woman who moved to Kosovo after independence. Warm, well-observed, and a good introduction to the texture of life there — villages, customs, food, the complicated daily negotiations of an unrecognised state.
The Fall of Yugoslavia by Misha Glenny covers the wider Yugoslav dissolution of the 1990s and provides the context for understanding how Kosovo got to where it is. Glenny reported from the region throughout the wars; his account is vivid and authoritative.
For the 1999 NATO intervention specifically, Waging Modern War by General Wesley Clark (the NATO Supreme Allied Commander during the Kosovo War) offers an inside account — useful for understanding how the conflict was managed from the Western side.