These are the books. Some think you should read in different orders, but this is one chronological order I found.
Rise of the Horde
*The Last Guardian (all books with an * can be purchased as Warcraft Archive. 4 books
Tides of Darkness
Beyond the Dark Portal
*Day of the Dragon
*Lord of the Clans
*Of Blood and Honor
War of the Ancients Trilogy includes the following 3 books
The Well of Eternity
The Demon Soul
The Sundering
Cycle of Hatred
The Sunwell Trilogy
Arthas Rise of the Lich King
Night of the Dragon
The Shattering
Stormrage
Thrall: Twilight of the Aspects
There is also an article on WoW Insider you can find here...
