Classical Education

• "The Lost Tools of Learning" by Dorothy Sayers

Liturgy

• Divinum Officium - The Divine Office (what was replaced with the Liturgy of the Hours)
• SanctaMissa.org - An online tutorial for the Traditional Latin Mass, with instruction audio, videos, and photos for both Priests and Altar Servers. 
• The Liturgical Year, by Dom Prosper Guéranger (HTML Vesion -- PDF Files)
• Liturgical Calendar of 1962
• "The Entire Liturgical Year: Its Meaning, Schema, and Customs" from HolyTrinityGerman.org
• CatholicLatinMass.org

Theology

• Dominican House of Studies - Works of St. Thomas - Here is a collection of many of Saint Thomas works in both Latin and English.
• The Devastated Vineyard, by Dietrich von Hildebrand. A must read for all devoted to the traditions of the Roman Catholic Church.