The Malleus Maleficarum (1486) 
translated by Montague Summers [1928]
This is the best known (i.e., the most infamous) of the witch-hunt manuals. Written in Latin, the Malleus Maleficarum was first submitted to the University of Cologne on May 9th, 1487. The title translates to "The Hammer of Witches". Written by James Sprenger and Henry Kramer (of which little is known), the Malleus remained in use for three hundred years. It had a tremendous influence in the witch trials in England and on the continent. This translation is in the public domain.
If you want to know more about the Malleous Maleficarum and the person who transcribed it for online presentation, please go to http://www.malleusmaleficarum.org/