Are you talking about the 10-vol. series edited in the 19th century by Roberts and Donaldson and available online from the "Christian Classics Etherial Library"? This is the most widely available version of the early Christian writers (before the Council of Nicea--the same edition also contains the "Nicene and Post-Nicene Fathers" who are from the 4th century and later). There are more up-to-date and readable versions of these writers: the Ancient Christian Writers series and the Fathers of the Church series. It so happens that both of these series are edited by Catholics, while the ANF series is edited by Protestants (and since it was edited in the 19th century, the bias is much stronger than it would be today). So if you can get a hold of any of the volumes in the ACW or FC series (if you can't afford them from amazon.com, try ordering them ILL from your nearest library) they are preferable. The plain fact is, though, that the ANF series remains the best or only source for many of us (including me these days, since I'm teaching at a school that doesn't have a very good library--obviously I can get the originals or a modern translation if I order them ILL, but for quick and easy reference, or for class assignments, I routinely use the ANF/NPNF edition). It's not ideal, and for scholarly purposes it always needs to be checked against a better translation or, preferably, the original Latin or Greek (or Syriac or whatever). But it will do for a basic introduction. Just remember that the notes, and sometimes the translations, are both outdated and biased against your theological perspective, so don't take them too seriously. (Translation: if you find something that seems to contradict Catholicism, don't run out and join the local Presbyterian church--instead, check one of the better, modern, Catholic versions, and/or read several works of good modern patristic scholarship on the question, including at least one Catholic work, and/or talk to a priest or Catholic scholar or online apologist or even me, an Episcopalian who is more or less fair-minded and agrees with Catholics over Protestants at least half the time).
