For a good historical overview from the mid-15th century to the end of World War II, try The Balkans Since 1453 by Northwestern University Professor L. S. Stavrianos (Holt, Rinehart and Winston, 1966).
Rebecca West's Black Lamb and Grey Falcon: A Journey Through Yugoslavia (Penguin Books, 1994) is a graceful history/travel journal that portrays Croatia in a Balkan context. West, who was a journalist, novelist, and critic, undertook her research in the Balkans with the idea of writing a travel book, but the result turned out to be a seminal work that illuminates the tangled history of the former Yugoslavia.
Croatia: A Nation Forged in War by Marcus Tanner (Yale University Press, 2001) is also a history of Croatia, but Tanner's book goes from the beginning of Croatia's history in A.D. 800 through the start of the millennium and includes the 1991-95 Homeland War.
Robin Harris's Dubrovnik: A History (SAQI, 2003) is an excellent historical overview of the former Republic of Ragusa and helps shed light on how Dubrovnik came to be the "Pearl of the Adriatic."