What with the Goth movement being so hot right now, many young people get curious about other alternative lifestyles with a darker edge to them... at least that which is perceived as dark by the mainstream. You should be careful not to get into something as serious as a religion just because your friends will think you're cool or you'll be rebellious against your parents. But if you're seriously interested, you'll find that there's much less to it than what the mainstream would have you believe.
Get it straight right now: Wicca is not witchcraft. To run around saying you pray to the devil and cast spells and have a familiar and so on and this makes you a Wiccan is an insult to Wicca and deliberately offensive besides. That being said, Wiccan beliefs tend to incorporate the idea that we mere mortals can manipulate nature in order to practice magic, and such is not that far removed from the monotheist religion's ideas that we can pray to a deity to have it work miracles for us. When Wiccans write of magic, they often spell it "magick".
Wicca is actually a nature-based religion. Its origins are widely debated, but it seems to borrow heavily from the Druidic and Pagan religions. There is a heavy focus on nature, the elements, and a pantheistic world-view, so it may also have elements of Hinduism mixed in. It is most definitely rooted in Europe, specifically Northern Europe, and furthermore incorporates some world-view from medieval European alchemy. Finally, the adherence to "harming no one" echoes the pacifist beliefs of the Buddhists. None of this is to say that Wicca derives from any of these, but merely to point out similarities as possible influences on Wicca, in the fashion that religions tend to share common core beliefs. But no Wiccan practitioner would deny that it does derive a lot from Paganism, as well as Pre-Christian Celtic and Teutonic beliefs.
Your new bible will be the "Book of Shadows". This is frequently copied by hand from generation to generation. However, some Wiccans also refer to their personal journal as a Book of Shadows, and it's similar to the concept of a grimoire. Excerpts from the original copy remain in static form, including the "Wiccan Rede" and "Charge of the Goddess". If you adhere to Gardnerian Wicca, you'll want a copy of "Witchcraft Today" on your shelf.
Gerald Gardner is the person who seems to have stumbled on a group of Wiccans in England and been initiated into their coven. fearing that the religion was in danger of dying out, Gardner wrote about it and popularized it, bringing it to the modern world. Thanks to his efforts, Wicca is a growing practice, with an exponential growth in Europe and the United States.
Wicca is also one belief system that emphasizes equality of the sexes, but sometimes elevates women to a higher level than men. The duality of their deity expresses this: there is a God and Goddess, but the Goddess is sometimes seen to be the greater of the two, since she contains and conceives all. Practitioners of Dianic Wicca take this a step further to say that the Goddess is complete to herself.
Let's have a spin through some of the core beliefs:
The spirit of the deity is invested in the spirit of the individual person.
Everything is connected to everything else. This is where the magic part comes in, because you can affect the universe through your actions.
Sexuality and the body is sacred. It is not to be considered dirty or immoral but beautiful, but nevertheless treated with respect.
We are all connected to the deity through a life-force.
Nature gives us religious inspiration, and since we are all connected with the universe both life and death are to be happily accepted as parts of the plan.
Every Wiccan is a member of the clergy.
Magic is real because the universe is magical and we are magical beings.
Every action you commit comes back to you three-fold.
That's the sum of most of it. there now, it doesn't sound as spooky as it did before, right? Be aware that Wicca is less structured than many religions, with a wide variety of beliefs and practices. Since it is more "liberal" than other religions, with an emphasis on equality, there is no hierarchy handing down the rules for the followers to obey. just about anybody is as good an authority on it as anybody else, and wide mutation of the practices and rituals are at least tolerated, if not encouraged.
Which makes it a safe enough subject to write about...