Here you will find several resources on non-canonical early Christian literature. (to be more populated soon)

Catechetics and Hymnody

The Didache — possibly the earliest catechetical document regarding Christian morals and Church Order.
Odes of Solomon — the earliest Christian hymn book.

Gospels

Protevangelium of James (Infancy Gospel of James) — details account of Mary and Jesus’ births. 
The Gospel of Thomas
 — Syrian text discovered in the early 20th century; dated around A.D. 200.
The Jewish-Christian Gospels — three possible texts used by Jewish-Christian sects.
Letter of the Apostles (Epistula Apolostorum) — actually considered a gospel by literary scholars, is said to have been written by the apostles.

Acts

Acts of Pilate (Gospel of Nicodemus) — depicts the details about the trial of Jesus, the conversations between Pilate and the Jews, the post-resurrection controversy, and the story of Joseph of Arimathaea.