Where do I start?
The best starting place for beginning your practice is reading. I know it's not what everyone likes to hear but it's very important. Pick up as many books as you can get your hands on. You can browse for books here on ModernWiccan.com to get an idea of what's available. Reading causes you to think; by thinking, instead of being told, you can come to your own conclusions about the Craft.The next step is meditating. Meditation will help you to clear your mind and relax your body. This way when you are ready to start casting spells, you can easily relax yourself and focus on your magickal works.
Get out in nature -- touch the trees and plants. Close your eyes. Try to feel the energy that emanates from them. Start skygazing. Feel how everything in nature is one with the universe, then make yourself feel the same. With practice, you will find that you are more peaceful and better able to concentrate on one thing at a time.
Ask yourself what you believe in. Write it down. This may change over time, but if you KNOW what you believe in, it makes the path a lot easier -- and also making it harder for others to steer you in the wrong direction.
Casting spells should come later. If you are a beginner and would like to jump right into spellwork, the best ones are cleansing, healing and grounding spells. They will prime you for the more complicated spells later on.
The Craft is a practice that allows you to think for yourself. Take advantage of this opportunity to do so.