There is Vodou and Voodoo
Haitian Vodou is a religion. Vodouisants honor and serve a select group of spirits called the Lwa. There is one God (called Bondye) and his Angels or Saints which would be the Lwa.
Voodoo is the New Orleans version of Hoodoo.
I'm not sure which one you are learning about. Learning about Hoodoo will get you a little bit closer to learning about Voodoo, however the best way to learn would be to talk to people who practice it.
As far as Haitian Vodou goes, there are many resources about it (books, websites, etc), just looking through some of the forums in this section you will find some info. Links to various other websites or information on it. There are also some books on it. Maya Deren's The Divine Horsemen is a good book that has a Documentary Film to go along with it. Kenaz Filan's The Haitian Vodou Handbook: Protocols for Riding with the Lwa is also a very good book.
Doing some research and talking to practitioners of it will be the best helper here.