the wheel of the year is the pagan calender, marked by eight major holidays called sabats. The wheel is the symbolic pattern of life and death that both the earth and the god and goddess follow throughout the year. (note that there is some debate as to whether Samhain, the 'new year', or Yule, the first holiday after the new year, is the real "start" of the year.)

Yule or Winter Solstice - usually Dec 21 - ( * )
Imbolc - Feb 1 or 2 - ( p )
Ostara or Spring Equinox - usually Mar 21 - ( * p )
Beltane - May 1 - ( p )
Litha or Midsummer's Eve or Summer Solstice - usually June 21 - ( * )
Lughnasadh - Aug 1 - ( h )
Mabon or Fall Equinox - Sept 21 - ( * h )
Samhain - Oct 31 or Nov 1 - ( h )

* = equinox or solstice
p = planting/fertility holiday
h = harvest holiday

The sun god is born at Yule, welcoming back the light from the long darkness, and the goddess sleeps after her labor. Come Imbolec, she awakens again, renewed, and the god is growing and life returns to the earth. Ostara is when the world becomse green and alive again, the god is a youth now and the goddess a lovely maiden. At Beltane they both come into their own and consummate the love that has been growing between them, and the goddess becomes mother. Litha is a time of the prime of the earth, the sun and light are at their peak and power and after this comes waning. Come Lugnasadh, the god begins his slow and gradual death, while the goddess reaps both joy and pain, from her pregnancy and her lover's decline. Mabon is the main harvest, the god prepares to die, and the goddess begins her waning as winter starts to take the world. And finally at Samhain, the old year ends as the god dies and travels to the otherworld, and the goddess, as crone, prepares her cauldron for his rebirth soon to follow at Yule.