Yoruba is the grandmother of all African magick (i.e., Voodoo, Santeria, etc.)

the Yoruba belief Sytem

Marie LaVeau- Famous Voodoo Queen of New Orleans

And of course, a site devoted to Yemaya with links to other African powers

I would also suggest the book "Jambalaya" by Luisah Tesh... its a great book about Voodoo and Women's magick