Advent

ADVENT The word Advent is from the Latin adventus for "coming" and is associated with the four weeks of preparation for Christmas. Advent always contains four Sundays, beginning on the Sunday nearest the feast of St. Andrew the Apostle, (November 30) and continuing until December 24. It blends together a penitential spirit, very similar to Lent, a liturgical theme of preparation for the Second and Final Coming of the Lord, called the Parousia, and a joyful theme of getting ready for the Bethlehem event.
Since the 900s Advent has been considered the beginning of the Church year. This does not mean that Advent is the most important time of the year. Easter has always had this honor.
The traditional color of Advent is purple or violet which symbolizes the penitential spirit. Religious traditions associated with Advent express all these themes.
http://www.ewtn.com/devotionals/advent/advent.htm

Advent prayer

Come, long-expected Jesus. Excite in me a wonder at the wisdom and power of Your Father and ours. Receive my prayer as part of my service of the Lord who enlists me in God's own work for justice.

Come, long-expected Jesus. Excite in me a hunger for peace: peace in the world, peace in my home, peace in myself.

Come, long-expected Jesus. Excite in me a joy responsive to the Father's joy. I seek His will so I can serve with gladness, singing and love.

Come, long-expected Jesus. Excite in me the joy and love and peace it is right to bring to the manger of my Lord. Raise in me, too, sober reverence for the God who acted there, hearty gratitude for the life begun there, and spirited resolution to serve the Father and Son.

I pray in the name of Jesus Christ, whose advent I hail. Amen.
http://www.catholic.org/prayers/prayer.php?p=350