I definitely recommend Hitler's World View: A Blueprint for Power by Eberhard Jäckel. He explains why Hitler felt it necessary to extinguish the Jews. Whereas Marx viewed history as class struggle, Hitler instead viewed history as racial struggle. Jäckel elaborates:

It is on this basis that the programmatic thinker Hitler confirms and defines for the political Hitler the dual, yet also unified, task of his life. He had to annihilate the Jews, thus restoring the meaning of history, and within the thus restored, nature-intended struggle for existence, he at the same time had to conquer new living space for the German people. Each of these tasks was inextricably linked to the other; indeed, they were the mutually necessary preconditions for each other. Unless the Jews were annihilated there would very soon no longer be any struggle for living space, nor therefore any culture, and consequently nations would die out; not just the German nation, but ultimately all nations. But if, on the other hand, the German people failed to conquer new living space, it would die out because of that and the Jews would triumph.

I would say that the explanation you are giving regarding the Holocaust depends on your target audience. The issue is a sensitive one, and the details can be harsh. Here are some sources where you can begin your search:

• http://www.theholocaustexplained.org/
• http://www.ushmm.org/educators/teaching-about-the-holocaust

I have a list of articles at home that I will update for you when I get there.