What is a good starting point for a study of the early Church? I'm very interested in the Early Church (after Christ's Ascension) and was wondering what Orthodox writings are available? So far, I have found Eusebius, Papias, Irenaeus, James the Martyr and Philo Judaeus. Does anyone have any additional suggestions? Basically, looking into the first century AD.
Epistle of Polycarp to the Philippians.

This and others may be found here.