Unfortunately, this subreddit is more geared toward academic history and research; the pedagogy of history education tends to play second fiddle. That's not to say that this isn't the right subreddit to ask such questions since there are a number of teachers, professors, and students who subscribe to it, just that getting responses can be kind of hit or miss. I’ve had modest success asking for teaching advice in the Friday-free-for-all when I was able to post early in the session so my answer wasn’t relegated to the bottom of the thread. You might also try posting in /r/teachers or /r/education. I’ve read some interesting discussions in both of those subreddits about history education.

Personally, I found Historical Thinking and Other Unnatural Acts by Sam Wineburg to be fascinating. I also enjoyed Teaching World History as a Mystery by Jack Zevin and David Gerwin. Both of these books show an important trend in history education right now that encourages students to “do” history in the classroom as opposed to merely listen to an expert lecture about it. This includes working with documents, constructing arguments, and using evidence to support assertions. Research has shown that engagement with the content in this way helps students learn more. Additionally, it is more in line with what historians actually do and what students are expected to do in college. Wineburg also talks about some of the history behind history education, which might be useful to you.

For actual classroom resources that carry out these ideas, the DBQ project, Stanford history project, and World History for Us All all demonstrate how these changes in history can be carried out effectively at the secondary level, as long as students are given the proper training and support to begin developing those critical thinking skills. I know that there is also a push to begin developing these skills earlier in elementary and middle school, but I don't have much experience working at that level.

In terms of debates among educators in the United States, the debates over curriculum and standards (e.g. Texas's standards debate or the literacy standards in common core) stand out to me as significant in the field of history education. I don't think educators and politicians have adequately reached a conclusion about how history should be taught and what content should be emphasized. How much cultural knowledge should students have and what constitutes the "correct" culture emphasized in public for diverse populations? Take a look at some curriculum theorists like Jonathon Kozol, Paulo Freire, and E.D. Hirsch for a variety of perspectives (there are lots of others but those three popped into my head first). They provide varied perspectives about the role of dominant cultural discourses in school that translates to history education better than almost any other subject in my opinion. Stemming from this debate, another key change is to include more minority voices. Textbooks and standards are attempting to move away from one narrative of national history to include those whose voices are often not heard at the secondary level. One interesting book that comes to mind is History Lessons: How Textbooks from Around the World Portray U.S. History by Dana Lindaman and Kyle Roy Ward. I've also encountered a number of lessons that compare and contrast how different textbooks represent historical events, then have students debate the value of different books. All of these are wrestling with the cultural connections underlying history curricula and the place of multiculturalism in American historical discourses.

EDIT: Expanded on a couple of my thoughts.

You might try posting your question(s) over at AskMetafilter (which would require a $5 membership fee); no guarantees expressed or implied, but it's a relatively intellectual forum.