Question: what are the three most important liturgical books?
Answer: Roman Missal. Sacramentary. ... 
Lectionary. Evangeliary (Gospel Book)
Liturgy of the Hours (Divine Office) Book of hours. ... 
General Roman Calendar. Tridentine Calendar. ... 
Roman Pontifical.
Roman Ritual. Benedictional.
Roman Martyrology. ... 
Gradual.