One of the best ways to prepare oneself for the onslaught of religion-based hostility is to read some of the very many books on the subject that have emerged over the last thirty years or so. But with such a wealth of titles available, and the field constantly expanding, the obvious question is where to begin? To which the obvious reply is, where are you starting from?
The question matters. You need to be clear on whether you want a simple introduction, a general but comprehensive overview for laypeople, or a scholarly tome filled with notes, sources and all the necessary qualifications, ifs and buts. Are you looking for approaches rooted in scripture, or Church teaching, or both?