The word Advent means "coming" or "arrival." The focus of the entire season is the celebration of the birth of Jesus the Christ in his First Advent, and the anticipation of the return of Christ the King in his Second Advent. Thus, Advent is far more than simply marking a 2,000 year old event in history. It is celebrating a truth about God, the revelation of God in Christ whereby all of creation might be reconciled to God. That is a process in which we now participate, and the consummation of which we anticipate. Scripture reading for Advent will reflect this emphasis on the Second Advent, including themes of accountability for faithfulness at His coming, judgment on sin, and the hope of eternal life.
The United Methodist Church has resources for the observance of Advent, including a series of appropriate meditations, an article on "Keeping the "Holy" in Holidays" and other reflections and aids to celebration.
Wikipedia's entry on Advent is here.
Our family uses an Advent wreath with dark blue candles and Advent devotional guides from Creative Communications for the Parish. We use an Advent calendar made out of felt that my Mother made for the kids when they were little. They still take turns, as they are here, placing one of the little pillows on the hanging felt panel. There are lots of Advent calendars online from:
St. Margaret Mary Parish
The German Embassy in London
Woodlands Junior School in England
The Episcopal Diocese of Washington
Iceland's House of Christmas
Yule Celebrations in Iceland
The United States Conference of Catholic Bishops
BBC Radio 3
A to Z Home's Cool Homeschooling
Christian Resource Institute
Ann Hetzel Gunkel
Q-Creative Productions at BanjoBunny
The Cat Who Laughed
a pattern to make one from Jan Brett.