We recently had a chance to visit a large church bookstore/church supply. Though I knew these books existed and was eager to get my hands on them, I finally had the opportunity to flip through a few. They are so good that we ordered the Twelve Great Feasts set and the Three Day Pascha Series!
Conciliar Press carries them all and describes them thus: "Elegant watercolor illustrations highlight the beauty of each of the Church's feast days. The simple, psalm-like poems are written especially for children, but the whole family will enjoy them."