Songs For Christmas. Book/CD. Published by Themes & Variations (TV.C41).
Songs for Christmas contains songs that you might use for performances in a holiday concert. "Sing a little Christmas" would be an excellent holiday concert opener. It's fast and fun and your students will love it. "In the Bleak Midwinter" is a total contrast - slow, lyrical and beautiful. Although many of the songs are in 2 or 3 parts, they would all be possible to perform in unison. Just teach the melody throughout for your younger or less experienced choirs.