I saw this in the NCTE Inbox, the email they send out every week or so. These guidelines, from the United States Holocaust Memorial Museum, are meant more for (I believe) secondary education, but they could work for college-level too, I think. They suggest contextualizing the Holocaust by examining the history of anti-Semitism. It would also be interesting, and I think some rhetoric teachers have done this before, to discuss Hitler's rhetoric and why it was so effective at the time (the kairos). So, if anyone is planning on talking about the Holocaust in class, read this first.