I found an excellent blog by a Dr. April DeConick, a Biblical Studies professor at Rice University. Her recent blog series is on “Creating Jesus” — she is up to Part 6. Part 2 is excellent for laying down the ground rules for the undertaking and an example to Atheists on how to prepare themselves to argue about the Gospels and Jesus (see my prev. post)
I think each person–Atheist, theist or otherwise–has there own theology, whether they are aware or not. When Atheists criticize Christians, I think that many come to the debate with a very unsophisticated Christology. For indeed Atheists have a Christology, though they may have never tried to articulate or systematize it. By thinking through one’s implicit Christology and realizing the other varieties out there, an Atheist can help make dialogue between Christians and Atheists much more productive. Dr. DeConicks site may help you with that.