Website of the Living Dead
My favorite builders of zombie lore are George Romero and Max Brooks, author of the book World War Z and the Zombie Survival Guide, both of which are fantastic reads. I never saw the movie.
The zombie mythos starts in Haitian culture. It's said that some voodoo practictioners could raise the dead to enslave them. The first use of the word "zombie" is believed to have appeared in an 1819 book by English poet Robert Southey, but this was likely an Anglicization of an African term. For instance, ndzumbi is a word from the Mitsogo language of Gabon, meaning "corpse," while the Kongo word nvumbi refers to a body without a soul. Haitians fought for independence from the colonists that enslaved them, scaring white people, who characterized them and their native religion as sinister and evil.

The first work of Western zombie fiction that we know of was The Magic Island, written by William Seabrooke in 1927. He described the zombies, or dead men working in the fields "The eyes were the worst. They were in truth like the eyes of a dead man, not blind, but staring, unfocused, unseeing." Pretty Spooky stuff! It was adapted into a movie called White Zombie in 1932. I saw it and thought it was really boring, so I'm not going to talk about it.