Vodou is form of Shamanism. It is practiced in Haiti, Africa, the United States and many other countries.
I am not a member of any Vodou House or Group. I also have not been initiated into this Tradition (the initiation ceremony is called Brule Zin, I believe). As such, I would be classified as a Bokor\Sorcerer. I do my own research on the Loa and Vodou practices from the few books available on the subject, and by speaking to the few Houngans and Mambos (Vodou Priests and Priestesses) that have been kind enough to communicate with me. Any information given me directly by a Mambo of Houngan will be credited with their name, should they allow me to give that. Otherwise, the information about Vodou given on this website is the result of my own research and experience.
My understanding of how Vodou views the Divine is that the Loa are parts of God. Bondye is the ultimate name of God in Vodou and means, "Good God". It is taught that Bondye cannot be directly communicated with by human beings, in his highest aspect. The Loa are the aspects of God that are directly involved in human affairs and can be contacted and worked with. The practitioner calls the particular Loa associated with his needs. This is not unlike the god-names of the Western Kabala.
At a certain phase in the Vodou path, the student is supposed to find their Patron Loa. This is the Vodou equivalent to the Holy Guardian Angel. Once he or she is found, the student should make regular offerings of energy or the loa's favorite things (though ultimately it is the energy that matters, as the Loa are energy, themselves) and build a working relationship with the Loa.
Much like the Degree system for Hermeticism, the more conscious the practitioner becomes of the Divine, the higher the degree attained. Each degree comes with new responsibility, but also additional spiritual power.