Learning about Luther

I recently browsed the May/June 2007 issue of Liberty: A Magazine of Religious Freedom.
It includes the first of two stories titled "The Scripturally Informed Conscience." This initial article by Nicholas Miller is subtitled Luther and Religious Liberty.
My history classes in high school and college touched on the Protestant reformation, but I doubt I could right a whole page about what I recall on the topic. Whether I was too young to understand the ramifications of the movement or the lessons themselves were only cursory, I'm not sure. At any rate, this author explores Luther's arguments for the separation of church of state. That's one nuance I know I didn't learn about in school. I'll have to make time to read up on Luther's ideas. Curiousity's got me now.