What site can you go to learn magic?

If you mean the sort of magic that stage magicians perform, then you may find the following links useful.

If however you mean Magick as opposed to magic, this is not something that can be learned from a website or from a book. Rather it is an ongoing process of learning and doing. There are many good books which will give you an introduction to the subject, and you can find them on your local bookstore's "Paganism/ New Age/ Spirituality" shelves.