Sacred Space has an Advent retreat online. They have daily readings for the season here. They have a link to an interactive Advent wreath.
The Episcopal order for Morning Prayer is here. The Catholic Liturgy of the Hours for today is here. A series of Advent wreath meditations provided by the United Methodist Church General Board of Discipleship is here. The Orthodox churches observe a 6-week Nativity Fast in preparation for Christmas, so they're already in the middle of their Advent season.
The Advent wreath graphic at the top of the post comes from The Curt Jester.