
The Lion, the Witch, and the Wardrobe is a very Christmassy book. Maybe it's because the first three times you see Narnia it is covered in beautiful wintery snow. Or maybe because C.S. Lewis actually added a character called "Father Christmas." Why do you think he did that? I think it's fascinating. He incorporated lots of mythical creatures from ancient folklore into Narnia, such as fawns and dryads and seapeople. But he also added a few characters that we recognize, like Bacchus (in Prince Caspian), and Father Christmas in LWW, who has continued to permeate our culture to this day. Nowadays, Santa Claus
When asked by a young fan what Aslan's "other name" was, C.S. Lewis included Christmas in his explanation:
"As to Aslan's other name, well I want you to guess. Has there never been anyone in this world who (1.) Arrived at the same time as Father Christmas. (2.) Said that he was the Son of the Great Emperor. (3.) Gave himself up for someone else's fault to be jeered at and killed by wicked people. (4.) Came to life again. (5.) Is sometimes spoken of as a Lamb (see the end of the Dawn Treader). Don't you really know His name in this world?"

In The Last Battle, Lucy (Narnia's example of faith) says,
"Yes," said Queen Lucy. "In our world, too, a Stable once held something inside it that was bigger than our whole world."Once again, an acknowledgment of Christmas and Christianity and Christ in the Chronicles. Yay, C.S. Lewis!!
Maybe you should re-read The Lion, the Witch, and the Wardrobe this December! Another great story is Luke 1 and 2, the story of the first Christmas. (And the whole Bible, of course! :)) You can conveniently read Luke online here.
And just for fun... Narnia Christmas Gift Ideas:
Narnia Fans Apparel
Fox Shop Official Merchandise

Narnia gifts from Zazzle
Narnia gifts from Cafepress
Narnia replicas and toys on Amazon
Wardrobe Necklace
Narnia Radio Theatre
The Voyage of the Dawn Treader movie