Continuning one's cartographic education long after having graduated from the college diploma program or the university degree program can be difficult. Courses in cartographer for cartographer are non-existent. Edward Tufte, however, provides the next best thing. His website is filled with book reviews, discussion groups, and essays on the graphic representation of data. His own books are an invaluable resource and available free to anyone who takes his day long course (looks like a great deal to me). On another site, some one has posted notes made during one of Tufte's lectures on maps. Comments like "avoid legends" could be an interesting discussion starter.

(Option 1, by the way, is the annual CCA conference.)