Unfortunately, since there is so little knowledge of the ancient Celtic traditions, there is really no single ritual to celebrate the holiday. Since all the New Age groups seem to have more or less completely made up their "rituals" I would advise you to read them but take them with a grain of salt. Keep in mind that the real Celts would not have had things like silver daggers (not for quite a long time, anyway--even the Romans were still using bronze or iron) or plants that don't grow in the areas where they live. They also wouldn't have spoken English, but I suppose we could let that pass since not many people speak "dead" languages anymore. My advice would be to read as many HISTORY books you can find about the celts. Learn about their culture and history, where they lived, etc. Make up something of your own, but use your knowledge of history rather than what a lot of New Agers made up (much of which seems to have little basis in history).

Peace--Keli