I would read them in this order:
Eusebius "History of the Church" (gives you historical context)
Then, get penguin's "Early Christian Writings" and read "The Didache," Clement of Rome's epistle, Ignatius of Antioch's epistles, Polycarp's epistle, the epistle of Barnabas. These are all very early 2nd century or late 1st century christian writers - the next generation after the apostles.
Then, either online or in their own book, find Justin Martyr's First Apology, Irenaeus of Lyon's "Against the Heresies" (in particular book 3), and Cyprian of Carthage (St. Vladimir's Orthodox Theological Semianry press has a wonderful edition of Cyprian).
From the second century, also from St. Vlad's seminary press (for a great edition), find a read Melito of Sardis "On Pascha" - an easter homily / liturgy from the mid second century that is, to my mind, one of the most beautiful summaries of the gospel.
After Cyprian, you might read Origin or Clement of Alexandria, but I'd skip right up to St. Athanasius "On the Incarnation."
Anything by Basil the Great, either of the two Gregories (Naziansus or the Theologian), John Chrysostom, Cyril of Alexandria - solid stuff all of it.
For more recent (and specifically Orthodox) readings, try St. John of Krondstadt (there are some organized groupings of his teaching that are easier to read than the original "My Life in Christ" he published). He's from the late 19th, early 20th century.
Before reading the recent stuff, though, read the old stuff - read the stuff they were basing their stuff on.
