Let me begin by saying, clearly, you cannot learn Vodou from books, but you can learn a little about it. The following are worthy reads and can help with context and background information. The links are to the US version of Amazon. While many other books exist, I include only ones I have personally read and can recommend.
Divine Horsemen: The Living Gods of Haiti by Maya Deren. Deren was a dancer, filmmaker, and choreographer who traveled to Haiti to study dance there, but fell in love with Vodou and eventually initiated into it. Mambo Maya’s book is dated now, but is a fascinating read and a good introduction to some essential information.
Sacred Arts of Haitian Vodou, Donald Cosentino, ed. This huge and pricey tome is a treasure trove of information and imagery, containing many essays written by scholars in the field. It is increasingly difficult to find, which is raising the price, but it truly worth the expense.
The Serpent and the Rainbow by Wade Davis. Written by an ethnobotanist, this famous book reads a bit more like an Indiana Jones script and is not without its flaws. All the same, it’s an interesting read and many of Davis’ observations and asides are quite fascinating. A grain of salt is needed due to the sometimes lurid nature of the book, meant for mass-market appeal. The more scholarly version of the book can be found with the delightful title Passage of Darkness: The Ethnobiology of the Haitian Zombie.
Tell My Horse: Voodoo and Life in Haiti and Jamaica by Zora Neale Hurston. Based on the author’s own experiences in Haiti, and as an initiate, this book is a sort of travelogue from a fascinating writer.
Island Possessed by Katherine Dunham. Based on travels to Haiti in 1936, Dunham, like Deren, made her trip initially to study dance. She details her time in the country, as well as her initiation into Vodou in what is a gripping read.
Nan Domi by Mimerose Beaubrun. Written by a Haitian woman, originally in Kreyol, this book is a personal account of her experiences learning from her aunt, in a form of country Vodou unrelated to better known asson lineages.
Voodoo in Haiti by Alfred Metraux – Another older book, with a lot of information that is dated to a degree and lacks a significant amount of context, but serves as an interesting introduction from the anthropological perspective.
The Drum and the Hoe by Harold Coulander. Another older tome, but interesting in its way, despite being dated and a little scattered. The lengthy list of Lwa is an interesting resource.
A Transatlantic History of Haitian Vodou by Benjamin Hebblethwaite. Using music and song, this book explores the history and development of Haitian Vodou, beginning with its roots in West Africa.
Haitian Vodou: An Introduction to Haiti’s Indigenous Spiritual Tradition by Mambo Chita Tann. A much more accessible book than many of the others, especially valuable for a lengthy section on Haitian history.
Vodou Culture by Michael Largey. A work of ethnomusicology, this is certainly a drier, academic read, but incredibly interesting if the subject matter intrigues you.