Each day has a deep historical background with a number of associations and traditions, but here is a quick outline of all eight Wiccan Sabbats. Links on each Sabbat name will take you to a more detailed page on the holiday (some still being written).
And I have a page of Pagan New Year's resolutions that are just for fun even though it's not really an official Pagan holiday.
Yule
Around Dec 21
Winter Solstice, Saturnalia
This is the solstice, which means the point in the year where the day/night length is at its peak. For Yule, it means that this is the shortest day and longest night of the year (the date shifts from the 20th to the 22nd each year). From this day onward, sunlight begins to return as the days start to lengthen again and we celebrate the symbolic rebirth of the Sun God. The holiday of Yule was celebrated long before Christians adopted the date for their own holiday. Many of the modern Christmas traditions we see today stem from these old Pagan customs from around the world.
Traditions: lighting a Yule log, decorating a tree indoors, gift giving
Correspondences: pine, cinnamon holly, myrrh
Imbolc
Feb 2
Candlemas, Brigid's Day
Imbolc is a day to celebrate the first signs of a new Spring, and it is also dedicated to the Celtic Goddess Brigid. Non-Pagans celebrate today as Groundhog Day, which is also related to seeing spring weather coming. Make some new starts in your life, as you give your home a thorough cleaning for the year.
Traditions: Burning fires, cleaning, making a bed for Brigid
Correspondences: carnation, chamomile, rosemary, fresh milk
Ostara
Around March 21
Spring Equinox, Lady Day
This is another Pagan holiday that has been overlaid with Christian meanings ( in this case, Easter). Eggs and bunnies are traditional symbols, representing new birth and new life. Plant the seeds of long-term goals on this day for extra success. Like with Yule, the date shifts and can be from the 20th to the 22nd. As an equinox, it means that the day and night on this day are the same length.
Traditions: Colouring or cooking with eggs, decorating with spring flowers
Correspondences: jasmine, daffodil, new wildflowers
Beltane
May 1
May Day, Walpurgis Night
The God reborn at Yule is now a man, and the sacred union between God and Goddess is consummated at this time of the year. Beltane is a celebration of fertility, growth, love and sexuality. However you personally celebrate Beltane, do it with joy and happiness.
Traditions: Dancing around a ribboned May Pole, lighting outdoor bonfires
Correspondences: Rose, vanilla, lilac.
Litha
Around June 21
Midsummer, Summer Solstice, Whitsun
Midsummer is the other solstice on the calendar and its the longest day of the year, usually on the 21st but it varies slightly as the other astronomical holidays do. The strength of the Sun God begins to wane as the days get shorter from now on. The Goddess has left her Maiden form of Imbolc and is now in her Mothering aspect. Refill your herb collection for the coming year on Litha for the most potent herbs.
Traditions: Fairy magick, collecting herbs
Correspondences: Orange, vervain, lemon, honeysuckle
Lammas
August 1
Lughnasadh
This is first of the three annual harvest festivals, and much of the symbolism for Lammas revolves around freshly harvested grains and bread. Sacrifices were common, though mostly symbolic, in order to ensure the continued success of the harvest through the next 2 holidays.
Traditions: Baking bread from scratch, making cornhusk dollies
Correspondences: corn, summer squash, sandalwood
Mabon
Around Sept 21
Autumn Equinox, Cornucopia
Day and night are equal again on this equinox, and the weather is growing colder as winter approaches. This is the second harvest festival of the year. Rituals of thanks at this time have brought about the modern holidays of Thanksgiving. Take some time to think about what you are thankful for on the next Mabon, even if you are not eating turkey.
Traditions: Making and drinking of wine, giving to the poor
Correspondences: grapes, patchouli, blackberries, cedar
Samhain
Oct 31
Hallowe'en, All Hallows
Samhain ( pronounced SOW-en) is the one Sabbat that is also widely celebrated among non-Pagans as Halloween. The God has died on this day, and the Goddess mourns him until he is reborn again at Yule. This brings on the darker phase of the year. It's the last harvest festival, and the end of the Wiccan year.
Traditions: Divination, remembering the dead, carving Jack o' Lanterns in pumpkins
Correspondences: pumpkins, apples, sage, mugwort
Being a witch or practicing witchcraft does not mean you have to celebrate these holidays. But doing so can help you appreciate the changes of energy through the cycle of the year, and get in touch with an earlier time.