Here you go. Enjoy.
USCCB Advent page.
Catholic Online's Christmast/Advent 2008 page - a great list of resources, prayers, activities, articles and more.
American Catholic's Advent FAQ
EWTN's Advent Page - Calendar, history, articles and more.
CatholicEducation.org's Advent traditions page.
Catholic Information Network's Advent Reflections - tons of good writing.
Our Sunday Visitor's Advent resources.
Catholic Exchange articles on Advent.
Catholic Encyclopedia on Advent.
Creighton University's Advent prayer page.
If you have any more, please leave in the comment box. I will try to update throughout the week, but blogging will be sporadic this week.