From Wikipedi
Samhain (play /ˈsɑːwɪn/, /ˈsaʊ.ɪn/, or /ˈsaʊn/)<1> is a Gaelic festival held on October 31–November 1. The Irish name Samhain is derived from Old Irish and means roughly "summer's end".<2> A harvest festival with ancient roots in Celtic polytheism, it was linked to festivals held around the same time in other Celtic cultures, and continued to be celebrated in late medieval times. Due to its date it became associated with the Christian festival All Saints' Day, and greatly influenced modern celebration of Halloween.
. . . .
Samhain is observed by various Neopagans in various ways. As forms of Neopaganism can differ widely in both their origins and practices, these representations can vary considerably despite the shared name. Some Neopagans have elaborate rituals to honor the dead, and the deities who are associated with the dead in their particular culture or tradition. Some celebrate in a manner as close as possible to how the Ancient Celts and Living Celtic cultures have maintained the traditions, while others observe the holiday with rituals culled from numerous other unrelated sources, Celtic culture being only one of the sources used.<10><23><24>
Celtic Reconstructionism
Celtic Reconstructionist Pagans tend to celebrate Samhain on the date of first frost, or when the last of the harvest is in and the ground is dry enough to have a bonfire. Like other Reconstructionist traditions, Celtic Reconstructionists place emphasis on historical accuracy, and base their celebrations and rituals on traditional lore from the living Celtic cultures, as well as research into the older beliefs of the polytheistic Celts. At bonfire rituals, some observe the old tradition of building two bonfires, which celebrants and livestock then walk or dance between as a ritual of purification.<4><6><18><24><25>
According to Celtic lore, Samhain is a time when the boundaries between the world of the living and the world of the dead become thinner, allowing spirits and other supernatural entities to pass between the worlds to socialize with humans. It is the time of the year when ancestors and other departed souls are especially honored. Though Celtic Reconstructionists make offerings to the spirits at all times of the year, Samhain in particular is a time when more elaborate offerings are made to specific ancestors. Often a meal will be prepared of favorite foods of the family's and community's beloved dead, a place set for them at the table, and traditional songs, poetry and dances performed to entertain them. A door or window may be opened to the west and the beloved dead specifically invited to attend. Many leave a candle or other light burning in a western window to guide the dead home. Divination for the coming year is often done, whether in all solemnity or as games for the children. The more mystically inclined may also see this as a time for deeply communing with the deities, especially those whom the lore mentions as being particularly connected with this festival.<4><6><18><24><25>
. . . .
Main article: Wheel of the Year
Samhain is one of the eight annual festivals, often referred to as 'Sabbats', observed as part of the Wiccan Wheel of the Year. It is considered by most Wiccans to be the most important of the four 'greater Sabbats'. It is generally observed on October 31 in the Northern Hemisphere, starting at sundown. Samhain is considered by some Wiccans as a time to celebrate the lives of those who have passed on, and it often involves paying respect to ancestors, family members, elders of the faith, friends, pets and other loved ones who have died. In some rituals the spirits of the departed are invited to attend the festivities. It is seen as a festival of darkness, which is balanced at the opposite point of the wheel by the spring festival of Beltane, which Wiccans celebrate as a festival of light and fertility.<26[br />
http://en.wikipedia.org/wiki/Samhain