well, candles or flashlights or something would help you to see outside if you're doing it at night [my Samhain circle is pretty much an night celebration, we go outside in the morning and have the night circle inside] bring a jack-o-lantern maybe for decoration and for seeing if you want. for my Samhain circle, candles aren't that important, we have the three candles on the alter and the four on the ground, but that's it. we do have this tradition in the morning circle, we write a resolution on a piece of paper [be it a bad habit, or a wish] and we burn it in the cauldron.
other non-candle things, ouija board and pendulum work to talk with our spirit friends, also we have a big meal, and set a few extra seats for them. if you want you can welcome the departed spirits to join you for the night, you should. light some incense for them would be nice too. this year, since some of my coven members have lost loved ones they're bringing a picture of them.
i don't really have fancy circles, we say a speech, meditate, then communicate with spirits and joke around. maybe it's wrong, but Samhain, we find, should be a fun time. it's usually more reserved for Imbolc and Mabon, Yules another fun one.