This Is The Faith by Canon Francis Ripley
Originally published in 1951 (with minor updates in 2002), the book covers the nature of God, the nature of man, the meaning of life, the nature of religion, the sources of Faith, the necessity of prayer, the duty of belief, the consequences of sin, the Commandments of God, the Holy Trinity, belief in Christ, the Redemption, the supremacy of the Pope, the Mystical Body of Christ, the Sacraments, the Mass, the priesthood, devotion to Mary and the Saints, what happens after death, the devotional life of a Catholic. Very interesting and very popular!