Samhain is a festival of the dead. It is believed that in this day the barrier between the world of the living and the world of the dead is at its thinnest, and the deceased can return to visit. It begins on October 31 at sunset, and ends on November 1 at sunset.
Adult Traditions include setting aside a plate of food for the dead, setting up Ancestor Shrines, carving Jack O'Lanterns, Zombie Walks, and cosplaying.
This year I will be carving two Jack O'Lanterns. There is a third and fourth pumpkin that were purchased, but it can't be used as a Jack O'Lantern since they don't have flat bottoms.
A new tradition I recently discovered sounds like fun. It's called All Hallow's Read. The idea is to get a scary book and leave it for someone to find and read. You can buy it new, used, in ebook format, as an audio book, and sometimes even at the library. I don't know if every library does this, but my local library will take donated books that others don't want and put them in a box. People are free to take the books out of the box and keep them at no charge.