This is a very cute website with a collection of stencils that can be used at Christmas. The stencils are arranged as an online advent calendar, which you could share with your children.  You could either visit this page daily, or save the images you like best right now.

Scroll to see the Advent Calendar and Click on individual pictures to print off a stencil.  Carefully use a craft knife or small pointed scissors to cut away the white areas of paper.  For the full effect on the wider stencils in the column for numbers 3, 7 and 23 set your printer to print as landscape format or size them by inches or centimetres yourself to suit you.  You can also print them onto Overhead Projector film as then they are washable and can be used year after year. 

Use the free stencils for decorating windows, cakes, friezes in schools and play schools or just for fun at home on a rainy day.  Size them all to small squares and make your own advent calendar in felt by adding one item every day.  Happy stencilling in Advent.