Buy and read Augustine’s Confessions at any cost. – John Piper
From the Publisher: 
“The Confessions of Saint Augustine is considered the all time number one Christian classic. Augustine undertook his greatest piece of writing with the conviction that God wanted him to make this confession. The Confessions are, in fact, an extended poetic, passionate, intimate prayer. Augustine was probably forty-three when he began this endeavor. He had been a baptized Catholic for ten years, a priest for six, and a bishop for only two. His pre-baptismal life raised questions in the community. Was his conversion genuine? The first hearers were captivated, as many millions have been over the following sixteen centuries. His experience of God speaks to us across time with little need of transpositions. This new translation masterfully captures his experience.”
About this Particular Translation:
“In 1990, the Augustinian Heritage Institute was founded by John E. Rotelle, OSA to oversee the English translation of The Works of Saint Augustine, A Translation for the 21st Century. This project was started in conjunction with New City Press. At that time, English was the only major Western language into which the Works of Saint Augustine in their entirety had not yet been attempted. Existing translations were often archaic or faulty and the scholarship was outdated. These new translations offer detailed introductions, extensive critical notes, both a general index and scriptural index for each work as well as the best translations in the world.The Works of Saint Augustine, A Translation for the 21st Century in its complete form will be published in 49 volumes. To date, 42 volumes have been published
From R.C. Sproul:
“It has been said that all of Western theology is a footnote to the work of Augustine. This is because no other writer, with the exception of the biblical authors, has had more influence on Christendom. Thomas Aquinas quoted Augustine heavily when he composed his Summa Theologica. When Martin Luther and John Calvin were accused of teaching new doctrine, they pointed to Augustine as an example of one who had taught the things they were teaching… His Confessions is one of the most important autobiographies ever written.”
Get Augustine’s Confession’s Here.
Also, check out:
The City of God
The Trinity
Teaching Christianity
On Genesis
The Old Guys 
I recently read Confessions after it being on my “to read” list for many years. It was interesting to stumble upon well known quotes from Augustine in their original context. My review https://lightenough.wordpress.com/2017/05/04/the-confessions-of-st-augustine-book-review/