There is a revered God, an assortment of spirits, and many rituals. Worshippers communicate with their God through the "loa" or spirits. This relationshiop is based on trust and mutual give and take. The people conduct ceremonies to honor them and loas, in return, are helpful in their lives.
The black magic aspects of this religion play a very minor role and is not typical of voodoo. In the early to mid 1900's, there were exaggerated claims about voodoo and movies portrayed followers as ignorant people who were obsessed with evil. Werewolves, zombies, the casting of spells and the use of voodoo dolls were sensationalized as the common practices of these people.
In actuality the use of black magic is rare but this stereotype remains with us even today.
The use of voodoo dolls is unheard of in Haiti and most places where the religion is practiced. The only recorded serious use of the dolls, among voodoo worshippers, was in the new Orleans area in the early 1900's. Hexes were cast to bring either good or bad luck to another person. The doll was used to symbolize that person. The sticking of pins into the doll was to reinforce and direct the spells that were cast.