So you have found Wicca, and it speaks to you. You want to learn more about becoming a Witch, maybe meet fellow Wiccans, gather some tools perhaps, and try casting your first spell. Where do you begin? The first step in becoming a practising Witch is to read, read, read! (I usually recommend Buckland to newcomers, as it contains a lot of rituals, and basic how-to-do-it info). I also highly recommend, The Essence of Magick, for all beginners as it explains how magick works and gives you a deep understanding of energy and witchcraft.
I also recommend that you meditate. Meditation is a way to step away from your running mind for a moment, and in that silence being able to go deeper into your soul. When casting spells, it's important that our minds are trained and focused, so that we cast the spells properly and direct the energy in the right way. Daily or regular meditation will help you a long way in achieving this kind of focus and becoming a powerful Witch. In meditation you can also access higher truths, your spirit guides, and your Higher Self . When you are in a meditative state, simply ask to connect with your Higher Self and ask him/her any questions you like. Answers will usually come through your intuition or some sensory experience. Know that you make the rules, and you forge your own spiritual path.
The only one rule that all Wiccans abide by is that of Harm None, as stated in the Wiccan Rede. Other than that, you pick up what you find along the way which you feel suits you and your beliefs and incorporate that into your practice. Stay curious, never stop growing and seeking; and most of all, enjoy yourself on this journey to becoming a Witch! (A note from Moonshine: some witches use evil magick, but most use good magic only. Are you one of the good ones? I hope so!)
Next you might want to start gathering some Witch tools. These don't have to be fancy or expensive. My first kit was very much DIY, collected in second-hand shops or clumsily crafted from various items I came across for a few pennies. Making your own tools will help you connect with them, and there will automatically be a strong bond. There are also plenty of beautiful tools available to buy if you can afford it. Search on Etsy, for example, where artists sell beautiful handmade items. Check out your local Wicca/New Age shop (if you have one) for both books and tools; they also sometimes have some sort of bulletin board, posting events for like-minded people. They also sometimes offer classes and courses. Also, see if you have a local meditation centre.
Another way is to go to open festivals in your area, spiritual fairs, renaissance fairs, and the like. Some of us prefer to go solitary, and some rather practice in a coven (a group of witches who meet up to perform rituals, celebrate Sabbats or cast spells together). It's up to you what you feel would be right for you. If you do decide to join a coven, make sure it is one you feel comfortable with, and one whose practices you agree with. (I strongly advise against any covens that worship Satan or practice dark magick. That's not Wicca and would be very harmful to yourself and others.) This Religious Tolerance page has some great information on how to contact witches and covens. They link to the Witches' Voice site, which has a Contact a Witch page, and tips for contacting witches, info on festivals/gatherings, and Wiccan shops in your area. It also gives listings for outside the USA. There is the Wicca Meetup Group (worldwide but heavily focused on the States). Meetup is a great website, just type in one of your interests or favourite activities to find all the meetup groups near you. And for us London witches, there is the London Wicca Meetup Group. Good luck, and most importantly enjoy and stay true to yourself. Read more: http://wiccanspells.info/learn-wicca-basics/becoming-a-witch/