I have studied and practiced Wicca for almost seven years.
There are a few things I want to point out... one be very careful with information you find online. Although much of it is very informative and useful, you need to remember that anyone can post almost anything on the internet. Two, Alder that is very impressive, however, I personally do not go around boasting of things, but I am not going to say that it is not possible you accomplished this. Calling down the moon, invoking a god or goddess, can result in amazing things. It all depends solely on the strength of your faith.
If you are interested in Wicca, one of the first books I ever tell anyone to read is "To Ride A Silver Broomstick" by Silver Ravenwolf. It is very easy to understand and will go over basic beliefs. She has a whole series of books that I found very useful in my early studies. I have progressed into more advance material and found that many of the other "basic" information I had looked at left quite a bit lacking.
Spells do work, but as has been pointed out before, there is much much much more to Wicca than just the spells. There is the herbal aspects, there is candle magick, there is learning of the Gods and Goddesses... and the list goes on and on. Studying Wicca simply for the power of spells with get you in trouble. The Wiccan Rede warns that whatever energy, good or bad, that you send out comes back to you times three. Basic law of Karma (for the full Wiccan Rede please see The Wiccan Rede)
Raven, I would recommend sticking mainly to books, or if there is a pagan store in your area, the store owners usually are very open and eager to teach and explain. You could also look for a mentor. At least that way you know the information you are getting is more correct than just looking it up online.
Tanya, I understand how your mind could have jumped directly to her when you found the raven on your lawn. However, it is somewhat unfair to assume. The raven is usually a messenger, unfortunately many believe that is is an evil omen. A raven does not necessarily only bring bad news. I obviously do not know the whole situation, but I just feel that I should assure that if she is truly Wiccan, and truly lives by the beliefs, she would not dare send harm your way. She could be following another form of paganism, one that is not as focused on the "light" or "white' aspects of it but could follow something darker, but as a true Wiccan, I would not even flirt with that type of magick... too dark and dangerous considering it would come back times three...