For a scholarly examination of serpent handling, read Ralph W. Hood's work. I've inserted links to his two books on the subject. He has published many excellent journal articles on it as well. They are well worth reading. You might supplement Professor Hood's work with that of Dennis Covington, the journalist who wrote Salvation on Sand Mountain, documenting his experience with serpent handling.
Serpent Handling: A Photojournalist's Reflections
Through covering Pastor Randy "Mack" Wolford's ministry, Washington Post photojournalist Lauren Pond had become friends with him. She was there when he died from handling a rattlesnake at a service. Wolford was a serpent handler who tried to spread that form of worship throughout Appalachia. You can read Pond's brief essay reflecting on her encounters with Wolford, as well as view photos documenting her experience.