Three books (Let’s Pray: First Prayers for Little Catholics, Good Manners in God’s House; and Francis Turmezei, My Little Missal, each 1950) in one volume.
978-0911845198 (TAN Books, hardcover, 2013) – available on Amazon here.
1930845194 (Neumann Press, hardcover, 2007, out of print)
The missal section provides a very basic descriptive summary of the Mass and age-appropriate commentary (e.g., that we pray for the dead to help the souls in purgatory). Probably best suited to the youngest of readers.