The Foundational Texts:

Aradia or the Gospel of the Witches of Italy - Charles G. Leland
The Secret Commonwealth: An Essay on the Nature and Actions of the Subterranean (and for the Most Part) Invisible People, Heretofore Going Under the Name of Elves, Fauns, and Fairies - Robert Kirk
The Fairy-Faith in Celtic Countries - W.Y. Evans-Wentz
The Golden Bough -  James George Frazer
The Greater Key of Solomon  - Samuel L. Macgregor Mathers
The Complete Art of Witchcraft: Penetrating the Secrets of White Magic - Sybil Leek
Fifty Years in the Feri Tradition- Cora Anderson
High Magic’s Aid - Gerald Gardner
Mastering Witchcraft: A Practical Guide for Witches, Warlocks & Covens - Paul Huson
Natural Magic - Doreen Valiente
Rebirth of Witchcraft - Doreen Valiente
Witchcraft for Tomorrow - Doreen Valiente
Witchcraft: a Tradition Renewed - Doreen Valiente and Evan John Jones
The Writings of Roy Bowers - (Robert Cochrane)
Apocalyptic Witchcraft - Peter Grey

Traditional Witchcraft:

The Roebuck in the Thicket - Evan John Jones & Robert Cochrane, editor Mike Howard
The Robert Cochrane Letters: An Insight into Modern Traditional Witchcraft - Robert Cochrane and Evan John Jones
The Forge of Tubal Cain - Ann Finnin
The Pillars of Tubal Cain -  Nigel Aldcroft Jackson & Michael HowardLiber Nox: A Traditional Witch's Gramarye - Michael Howard
Call of the Horned Piper - Nigel Aldcroft Jackson
Masks of Misrule - Nigel Jackson
Grimore for Modern Cunning Folk - Peter Paddon
Letters from the Devil's Forest - Robin Artisson
The Witching Way of Hollow Hill - Robin Artisson
The Horn of Evenwood - Robin Artisson
Azoetia: Grimoire of the Sabbatic Craft -  Andrew D. Chumbley
Opuscula Magica. Volume I: Essays on Witchcraft and the Sabbatic Tradition - Andrew D. Chumbley and Daniel A. Schulke
The Devil's Dozen-Thirteen Craft Rites of The Old One - Gemma Gary 
Cecil Williamson's Book of Witchcraft-A Grimoire of the Museum of Witchcraft - Steve Patterson
Serpent Songs - Editor:  Nicholaj de Mattos Frisvold

Specific Cultural Traditions:

Balkan Traditional Witchcraft - Radomir Ristic
Practical Magic in the Northern Tradition -  Nigel Pennick
Irish Witchcraft and Demonology - St. John D. Seymour
The Devil's Plantation: East Anglian Lore, Witchcraft & Folk-Magic- Nigel Pearson
Traditional Witchcraft a Cornish Book of Ways - Gemma Gary
The Black Toad - Gemma Gary

General Craft:

Wheel of the Year - Pauline Campanelli
Witches All - Elizabeth Pepper
Irish Witchcraft from an Irish Witch - Lora O'Brien
Magical Ritual Methods - William G. Gray
Seasonal Occult Rituals - William G. Gray
Ecstasies: Deciphering the Witches' Sabbath - Carlo Ginzburg and Raymond Rosenthal

History:

The White Goddess: A Historical Grammar of Poetic Myth - Robert Graves
The History of the Devil: The Horned God of the West - R. Lowe Thompson
Witchcraft and Society in England and America, 1550-1750 - Marion Gibson
Cunning-Folk & Familiar Spirits: Shamanistic Visionary Traditions in Early Modern British Witchcraft and Magic - Emma Wilby
Witchcraft in Tudor and Stuart England - Alan MacFarlane
Singing With Blackbirds: The Survival of Primal Celtic Shamanism in Later Folk -Traditions by Stuart A. Harris Logan
The Pattern Under the Plough - George Ewart Evans. Faber and Faber.
The Secret Teachings of All Ages - Manly P. Hall.
Shamanism: Archaic Techniques of Ecstasy - Mircea Eliade
Witchcraft in Europe, 400-1700: A Documentary History - Alan Charles Kors and Edward Peters
Shamans Sorcerers and Saints: A Prehistory of Religion - Brian Hayden
Myths and Symbols in Pagan Europe - H.R. Ellis Davidson
The Pagan Religions of the Ancient British Isles: Their Nature and Legacy - Ronald Hutton
Popular Magic: Cunning-folk in English History - Owen Davies

The Know How:

Complete Book of Incense, Oils & Brews - Scott Cunningham
Practical Candleburning Rituals: Spells and Rituals for Every Purpose - Raymond Buckland
Magic and Husbandry- The Folk-Lore Of Agriculture; Rites, Ceremonies, Customs, And Beliefs Connected With Pastoral Life And The Cultivation Of The Soil; With Breeding And The Care Of Cattle; With Fruit-Growing, Bees, And Fowls – Lewis Dayton Burdick

Wortcunning: 

For Info on plants see my other site, it's literally a giant bibliography.
Witchcraft Medicine: Healing Arts, Shamanic Practices, and Forbidden Plants - Claudia Müller-Ebeling, Christian Rätsch, and Wolf-Dieter Storl
Pharmako Trilogy -  Dale Pendell
Cunningham’s Encyclopedia of Magical Herbs by Scott Cunningham
Herbal Rituals. Judith Berger
The Herb Book by John Lust
Herbal Medicine-Maker’s Handbook: A Home Manual by James Green
Magical and Ritual Use of Herbs - Richard Alan Miller
Blackberry Cove Herbal: Healing With Common Herbs in the Appalachian Wise-Woman Tradition -Linda Ours Rago
Leechcraft: Early English Charms, Plant-lore and Healing - Stephen Pollington
Witches, Midwives, and Nurses: A History of Women Healers  - Barbara Ehrenreich and Deirdre English
Viridarium Umbris: The Pleasure Garden of Shadows, by Daniel Alvin Schulke. Xoanon Publishing.
Thirteen Occult Pathways to Herbalism, Daniel Alvin Schulke
American Household Botany. 1600-1900. Judith Sumner.

Folklore:
A Dictionary of English Folklore - Jacqueline Simpson and Steve Roud
Make Merry In Step and Song: A Seasonal Treasury of Music, Mummer's Plays & Celebrations in the English Folk Tradition - Bronwen Forbes
The Folklore of Plants T.S. Thistleton Dyer.

Appalachian Folk Magic/ Medicine:

Appalachian Ethnobotany Database I Created
Folk Medicine in Southern Appalachia. Cavender, Anthony P. 
This List from Backwaters Witch
Frank C. Brown North Carolina Folklore collection, especially book 7
Signs, Cures and Witchery, Gerald Milnes
The Silver Bullet and other American Witch Stories, Hubert J. Davis
American Witch Stories, Hubert J. Davis
Green Hills of Magic: West Virginia Folk Tales from Europe, Ruth Anne Musick
​Staubs and Ditchwater: a Friendly and Useful Introduction to Hillfolks' Hoodoo, Byron Ballard​
​Asfidity and Mad-Stones: A Further Ramble Through Hillfolks' Hoodoo, Byron Ballard 

Amjad, Hassan. Folk Medicine of Appalachia: A Vanishing Tradition. United States, Hassan Amjad, 2005.

Hexerei, Braucherei, Powwow

Long Lost Friend — John George Hoffman

Bilardi, C. R. The Red Church Or the Art of Pennsylvania German Braucherei. United States, Pendraig Publishing, 2009.

Donmoyer, Patrick J. Powwowing in Pennsylvania: Braucherei and the Ritual of Everyday Life. United States, PA German Cultural Heritage Center, Kutztown University.

Kriebel, David W. Powwowing among the Pennsylvania Dutch : a traditional medical practice in the modern world. United States, Pennsylvania State University Press, 2007.

Orth, Richard L.T. Folk Religion of the Pennsylvania Dutch: Witchcraft, Faith Healing and Related Practices. United States, McFarland, Incorporated, Publishers, 2018.

American Folk Magic: General

Hutcheson, Cory Thomas. New World Witchery: A Trove of North American Folk Magic. United States, Llewellyn Publications, 2021.

Other Witch's Reading Lists:
Archaic Honey's Resource List 
The Witches Resistance Action List
Poison Path Resource Guide