- The Early Church by Henry Chadwick
- Four Witnesses: The Early Church in Her Own Words by Rod Bennett Recommended to me by Patricia, it's an interesting and compelling read
- Beginning to Read the Fathers by Boniface Ramsey
- Christ In His Fullness by Bruce Sullivan Written by a man who has become not only a good friend of ours, but our sponsor in the Church and our children's godfather, he used to be a preacher in our former church.
- Rome Sweet Home: Our Journey to Catholicism by Scott Hahn and Kimberly Hahn An interesting read, in some ways, but written in an annoying "He said, she said" style.
- Lead, Kindly Light: My Journey To Rome by Thomas Howard I think I could read anything written by Thomas Howard. He's a great writer, and I don't think I've read anything better.
- By What Authority?: An Evangelical Discovers Catholic Tradition
by Mark P. Shea Blogger Mark Shea was one beginnings of the rabbit trails that lead us to Catholicism.
- The True Church: The Path Which Led a Protestant Lawyer to the Catholic Church; Christian Theory, Doctrine and Discipline by Peter H. Burnett
- Apologia Pro Vita Sua by John Henry Newman
- Catholicism and Fundamentalism: The Attack on "Romanism" by "Bible Christians" by Karl Keating
- Evangelical Is Not Enough: Worship of God in Liturgy and Sacrament
by Thomas Howard
- The Catholic Verses: 95 Bible Passages That Confound Protestants
by Dave Armstrong
- One, Holy, Catholic and Apostolic: The Early Church Was the Catholic Church by Kenneth D. Whitehead
- An Essay On The Development Of Christian Doctrine by John Henry Newman
- Orthodoxy by G.K. Chesterton
There are probably a million other things I could list. We also read a lot of blogs, a lot of articles, and listened to many Podcasts (Fr. Riccardo is worth finding on iTunes, if you like that kind of thing).
Feel free to add any other good book suggestions in the comments.