Our evenings in Advent begin after dinner with the Jesse Tree reading and ornament, followed by the lighting of the Advent Wreath and prayer and Christmas song, and then the children get to open their chocolate Advent calendars as a final treat each evening.
Here are some Advent Wreath prayers to choose from:
I particularly like this set of prayers from St. Charles Borromeo Catholic Church, but here are some other prayers for the Advent Wreath:
more traditional
shorter (look under the alternate prayer for each week for the shorter version)
longer and more modern
On the First Sunday of Advent, the head of the household can say this blessing of the Advent Wreath
"O God, by whose word all things are sanctified, pour forth thy blessing upon this wreath, and grant that we who use it may prepare our hearts for the coming of Christ and may receive from Thee abundant graces. Through Christ our Lord. Amen."
(from catholicculture.org)