. . . so I'm going to take the easy way out and post a bit of bibliography on the topic at hand. I find that a lot of writings about Mary all sound the same, because they are drawn into the typical Catholics vs. Protestants talking points that I'm trying to avoid. There are a few books that I want to recommend, however:
The most helpful book I've encountered on the topic is
Hilda C. Graef, Mary: A History of Doctrine and Devotion. Volume I: From the Beginnings to the Eve of the Reformation.
This work simply presents extracts of Christian writings about Mary in chronological order, so you can read for yourself what was said about her in the early centuries of the church. This is the resource one needs in order to be guided by the Vincentian Canon.
A shorter book that covers the place of Mary from the first century up to the present is Jaroslav Pelikan, Mary through the Centuries. New Haven: Yale University Press, 1996.
If you really want to read a Catholic and Protestant hashing out their competing views, an enjoyable, irenic example is
Dwight Longnecker and David Gustafson. Mary: A Catholic-Evangelical Debate.
This one is actually kind of cool theological mash-up, the authors (one Catholic, one Prod) having been college classmates at Bob Jones University. As good a book as any to give you an example of the circles you can argue through about this topic.
Scot McKnight has a book out on Mary that I haven't read yet. I read his article in Christianity Today and was underwhelmed, so I haven't been eager to pick it up. McKnight seems keen to prove that Mary was a lot feistier than we have all been led to believe, but his arguments ring hollow for me. I can understand why we would like her to be feisty--a radical, subversive Mary is much more interesting--but I think McKnight's presentation is overstated. "Well-behaved women rarely make history," they say, but Mary may well be a counterexample. (Click the link to see the wide range of merchandise you can purchase to declare that sentiment. Note what the first example is an apron. Deliberate irony? You can also get the slogan on a thong, which I think is not quite the sort of bad behavior the saying has in mind.)