I bring it up every year, but I'll say it again. If you even think you might like a daily devotional (that doesn't even have to be daily, by the way) during Advent, buy God with Us: Rediscovering the Meaning of Christmas. It includes reflections from the likes of Kathleen Norris and Richard John Neuhaus, among others, and in the midst of their thoughts, prayers, and Scripture readings you will find beautiful paintings and prints from throughout the ages that help tell the story of Jesus' birth. An adult Advent calendar. I read it every year, and since my devotional life is quite sporadic, every year it is new. Last year, I seem to have read the Second Sunday of Advent, because I remember it. But the first Thursday of Advent was quite new to me. I can't recommend it highly enough.
But. If you don't want to shell out $20 or if you know you won't even begin to read a book about Advent, then at least check out some lovely posts from other writers: