Here are several more ideas/printables that caught my eye...
FREE! "Jesse Tree: God's Big Advent Story"
Daily printable devotions for Advent along with printable Jesse Tree ornaments available both color and black and white from Faith Alive/CRC
Here is a blog post full of suggestions for using Jesse Tree: God's Big Advent Story. I like this project because it goes BEYOND Christmas Day with activities.
Here is a great FREE Jesse Tree Advent Family Devotional, with ornaments you can print out and color and daily readings/devotions from Today devotional.
Easy Advent calendar suggestion using envelopes:
Advent in Two Minutes
Here's an excellent video (more for parents or good readers) that explains what Advent is. Would be great in worship, or to share on your Facebook page for a bit of education for the adults in your congregation.)
Advent in Two Minutes, by Busted Halo.