Wicca, founded around the 1940s by Gerald Gardner, is based on witchcraft, as well as bits and pieces from other older Pagan religions/practices, free-masonry and ceremonial magic.
Traditionally it is an orthopraxic, mystery religion, that is oath bound and requires coven initiation. It is the Priesthood of two specific deities and it is fertility centered. You will not find all that much info on Trad Wicca from books/internet, as most of what is discussed refers to Eclectic NeoPagan paths (often mislabeled as Eclectic, Solitary Wicca), which are based on the non-oath bound (outer-court) parts of Wicca. For more info I would suggest reading the following... http://hagstone.blogspot.com/2011/06/wicca.html
Other than that it's a matter of honoring the Gods, and celebrating the cycles of birth, life, death and rebirth - through the passing of the seasons.
Wicca is the religious cult of modern witchcraft, especially an initiatory tradition founded in England in the mid 20th century and claiming its origins in pre-Christian pagan religions. The word Wicca comes from the old English word "wicca," meaning "witch."