Though Gardnerian Wicca is primarily an experiential and oral tradition, it can help to get some insights into the practice by reading books. This is a short list of books that will help seekers in the right direction.
Witchcraft Today by Gerald B. Gardner
The Meaning of Witchcraft by Gerald B. Gardner
Witchfather: A Life of Gerald Gardner by Philip Heselton
Witchcraft for Tomorrow by Doreen Valiente
Natural Magic by Doreen Valiente
The Triumph of the Moon by Ronald Hutton
Wicca: A Guide for the Solitary Practitioner by Scott Cunningham
Wicca: A Comprehensive Guide by Vivianne Crowley
All Acts of Love and Pleasure: Inclusive Wicca by Yvonne Aburrow
Wicca for Beginners: Fundamentals of Philosophy and Practice by Thea Sabin
A Witch Alone: Thirteen Moons to Master Natural Magic by Marian Green