here is Peter Kirby's suggested reading list :
The original has links.
Primary Sources in Translation
The Nag Hammadi Library in English by James M. Robinson, et al.
This book contains translations of all the documents discovered at Nag Hammadi. The texts reveal the Gnostics as they saw themselves, not as the
Church Fathers characterized them, and thus these texts have provided a wealth of information for the study of ancient Gnosticism and, by extension,
ancient Christianity. The translation has been conducted by a team of scholars, correctly noting the lacunae and those places where reconstruction of
the text is conjectural or where the English equivalent is approximate. This ensures an accurate translation. Moreover, the notes alone justify the
low, mass paperback price of the book. Each one of the documents is introduced with excellent notes on estimated dating and other information critical
to an understanding of the text. This volume is a welcome addition to the personal library of any person who professes an interest in the history of
early Christianity, and it is absolutely necessary to anyone who is interested in ancient Gnosticism.
New Testament Apocrypha : Gospels and Related Writings by Wilhelm Schneemelcher (Editor), R. M. Wilson (Translator)
This is the standard scholarly work with up-to-date translations of all the ancient noncanonical Christian writings. This volume contains Oxyrhynchus
840, Papyrus Egerton 2, Oxyrhynchus 1224, Cairensis 10 735, the Fayyum Fragment, the Strasbourg Coptic Papyrus, the Secret Gospel of Mark, the Gospel
of Thomas, the Gospel of the Nazareans, the Gospel of the Ebionites, the Gospel of the Hebrews, the Gospel of Philip, the Gospel of the Egyptians, the
Gospel of Peter, the Book of Thomas, the Freer Logion, the Epistula Apostolorum, the Apocryphon of James, the Dialogue of the Saviour, the First
Apocalypse of James, the Dialogue of the Saviour, the First Apocalypse of James, the Second Apocalypse of James, the Letter of Peter to Philip, the
Gospel of the Four Heavenly Regions, the Gospel of Perfection, the Gospel of Truth, the Sophia Jesu Christi, the Dialogue of the Redeemer, the Pistis
Sophia, the two Books of Jeu, the Gospel of the Twelve, the Lukean Gospel of the Twelve, the Memoria Apostolorum, the Manichean Gospel of the Twelve
Apostles, the Gospel of the Seventy, the Gospel of Matthias, the Gospel of Judas, the Apocryphon of John, the Fragments of a Dialogue between John and
Jesus, the Apocryphon of James, the Gospel of Bartholomew, the Questions of Mary, the Gospel of Mary, the Genna Marias, the Gospel of Cerinthus, the
Gospel of Basilides, the Gospel of Marcion, the Gospel of Apelles, the Gospel of Bardesanes, the Gospel of Mani, the Protevangelium of James, the
Infancy Story of Thomas, the Arabic Infancy Gospel, the Gospel of Pseudo-Matthew, the Abgar Legend, the Gospel of Nicodemus, the Gospel of
Bartholomew, and the Gospel of Gamaliel.
New Testament Apocrypha : Writings Relating to the Apostles Apocalypses and Related Subjects by Wilhelm Schneemelcher (Editor), R. M. Wilson
This second volume contains the Kerygma Petri, the Epistle to the Laodiceans, the Correspondence between Seneca and Paul, the Pseudo-Titus Epistle,
the Acts of Andrew, the Acts of John, the Acts of Paul, the Acts of Peter, the Acts of Thomas, the Acts of Peter and the Twelve Apostles, the
Pseudo-Clementines, the Ascension of Isaiah, the Apocalypse of Peter, the Fifth and Sixth Books of Esra, the Christian Sibyllines, the Book of
Elchasai, the Coptic Apocalypse of Paul, the Coptic Apocalypse of Peter, the Apocalypse of Paul, and the Apocalypse of Thomas.
Introduction to the New Testament
Who was behind its making and what did they have to say?
Introduction to the New Testament: History, Culture, and Religion of the Hellenistic Age by Helmut Koester
It is foolish to try to study the New Testament without looking at its context. Koester provides a survey of the background of the times that is
brilliant in its scope.
History and Literature of Early Christianity by Helmut Koester
This is the second volume in the introduction by Harvard professor Koester. It is my personal favorite NT introduction.
The History and Theology of the New Testament Writings by Udo Schnelle
Cowboy X can't say enough good things about this one. And, hey, I like it too!
An Introduction to the New Testament by Raymond Brown
A prolific and respected New Testament scholar wrote this NT introduction for the layman at the height of his career.
Who Wrote the New Testament? by Burton L. Mack
Mack offers a portrait of the development of mythologizing that became the New Testament.
The Jesus Puzzle by Earl J. Doherty
Without a doubt the best book expounding a Jesus Myth theory.
The Jesus Mysteries: Was the 'Original Jesus' a Pagan God? by Timothy Freke and Peter Gandy
Popular book, but I was not impressed. Watch out for those bloopers.
The Jesus Myth by G. A. Wells
Wells has allowed that there may have been a historical Jesus in Galilee yet maintains that the Jesus of early Christians (e.g. Paul) was a shadowy
figure of the indefinite past.
Jesus : One Hundred Years Before Christ by Alvar Ellegard
A variation on the Wellsian theme. Includes a stylometric argument for dating the gospels.
Deconstructing Jesus by Robert M. Price
Actually, Price addresses a bunch of different topics in a way that will be interesting even to the staunchest HJ believer.
OK, so maybe there was a historical Jesus . . . did he prefer Pepsi or Coke?
Jesus of Nazareth, King of the Jews by Paula Fredriksen
Argues that the crucifixion is explained by an eschatological Jesus.
The Historical Jesus: A Comprehensive Guide by Gerd Theissen and Annette Merz
Delivers what it promises. See my review.
The Historical Jesus by John Dominic Crossan
The result of years of labor examining the Jesus tradition and the ancient Mediterranean culture.
Jesus: Apocalyptic Prophet of the New Millenium by Bart Ehrman
Ehrman suggests that only later texts (such as Luke and Thomas) have a realized eschatology (i.e. the kingdom is here now).
Studying the Synoptic Gospels by Margaret Davies, E. P. Sanders
Discussion of the synoptic problem, form criticism, and other topics.
Jesus After 2000 Years by Gerd Luedemann
Useful commentary on the ancient gospels with an emphasis on historicity.
The Five Gospels by Funk et al.
The results of the deliberations of a team of researchers that made a big splash in the media.
Gospel Parallels: A Synopsis of the First Three Gospels
Presents Matthew, Mark, and Luke in a parallel format; this book is particularly helpful when studying the 'Q' document.
The Gospel of Thomas
In my mind, the most fascinating text in early Christianity.
The Gospel of Thomas and Jesus by Stephen J. Patterson
Features a comprehensive argument for the independence from the canonicals of most sayings in Thomas.
The Gospel of Thomas by Richard Valantasis
A commentary on the Greek fragments in themselves as well as the Coptic text, this book emphasizes the ascetic tendencies of Thomas.
The Gospel of Thomas by Stevan Davies
Davies does a commendable job in making Thomas make sense.
The Early Church
The Gnostic Gospels by Elaine Pagels
An exploration of the sociological factors that shaped orthodoxy. (Read this book instead of her new Beyond Belief: The Secret Gospel of Thomas, which
isn't really about Thomas.)
St. Paul Versus St. Peter: A Tale of Two Missions by Michael Goulder
A revival of the Judaistic-Hellenistic dialectical theory of Christianity's origins.
The Changing Faces of Jesus by Geza vermes
An overview of the portraits of Jesus found in John, the synoptics, etc.