The website anglomaniacy.pl has a lot of sources for teachers.
There is a special section for songs. You can find traditional songs and Christmas carols. Each song and carol has an online link where you can hear it. There is also a flash movie with the lyrics of it and some pictures about the songs.
To help teaching, they also offer printable pages with colouring pictures, the lyrics, the scores for guitar and piano and different activities to work on the topic.