One thing we’ve found helpful during December is to celebrate Saint Nicholas. There are lots of lovely story books out there about him, and his story is a combination of fact and myth. What I love is that our traditions of gift giving and specifically Father Christmas are linked to him.
I really like this book: The Legend of Saint Nicholas by Anslem Grun, as it leaves open the option for Santa to be ‘real’ or not, depending on how you celebrate it, and it has lovely pictures.
We’ve also used the Godly Play story of Saint Nicholas which uses simple language and items to represent different aspects of the story.
We have also adopted the tradition of leaving out our shoes or slippers on the evening of Saint Nicholas Day, 6th December. In the morning we find coins in them!
This wiki page has lots of Saint Nicholas traditions from different cultures, but you can google and find your own!