Here are some books related to Christian history that I recommend. Please note that these are affiliate links and by purchasing them, you are supporting this podcast and blog.
Augustine, City of God (Penguin Classics)
Henry Bettenson, Documents of the Christian Church
John Calvin, Institutes of the Christian Religion
Eusebius, The History of the Church: From Christ to Constantine (Penguin Classics)
Justo Gonzalez, The Story of Christianity, Vol. 1: The Early Church to the Dawn of the Reformation
Justo Gonzalez, The Story of Christianity, Vol. 2: The Reformation to the Present Day
Gordon Heath, Doing Church History: A User-Friendly Introduction to Researching the History of Christianity
Michael Holmes, The Apostolic Fathers: Greek Texts and English Translations
Kenneth Scott Latourette, A History of Christianity, 2 Volume Set
Marvin Meyer, The Gospel of Thomas: The Hidden Sayings of Jesus
N. T. Wright Paul: A Biography