1. Teach about Jesus: It's important that Christian families celebrate Christmas for the real reason which is that Jesus Christ was born to save the world from sins, and eternal separation from God. Your kids while they may not be able to understand the meaning behind the story can still learn the story and be able to know what happened. Always make sure that Jesus is front and center.
2. Avoid a works based Santa: Okay this one might get me in trouble with parents but here goes. Teaching kids that if they are good then Santa will visit them, is worked based rewards. I can see no way of allowing Santa to teach children about Jesus and yet have the whole point of Santa giving a gift being that the child earns it by being good. I know that the Santa threat has been a helper for parents around this time of year, but would not be better to teach our children to be good, because oh I don't know our God commands us to be good. "Be Holy for I am Holy" 1 Peter 1:16. We can punish our children when they misbehave, but should not showing them that right and wrong, come from God. This is what we believe is it not. This also shows that even when they are bad they can still receive the gift from Santa. The idea being here that Jesus as salvation from Christ is not dependent upon our good works, getting gifts from Santa is not dependent upon our children's good works.
3. Don't let them believe in Santa too long: I know there is a thing about being a child and having innocence and all, and that's cute, but maybe the reason we it takes so much longer for children to grow up is because we don't let them. One way or another your child is going to stop believing in Santa, because he isn't real. If we let our children go on believing in something that isn't real then I think we run the risk of distorting the gospel. I think about around the age of 8 is when we need to let our children know that Santa is not real. This doesn't mean we can't still give presents or even say that they from Santa, but is should be made known that you are Santa at that point.
4.Follow Up: We need to make sure that we keep raising our kids and don't stop when they get old enough to kinda take care of themselves. As kids get older you need to explain to them the deeper meaning behind the stories they have been learning. Perhaps as you tell kids the truth about Santa you can also tell them the truth about Jesus. Let them that the God you believe in is real, and could be their God too. Teach them the gospel. That's right you can evangelisie to your kids.