Sergio in the comments called my attention to the fact that Michael Wildt's important book about the central cadre of the SS is now available in English: An Uncompromising Generation: The Nazi Leadership of the Reich Security Main Office (George L. Mosse Series). Wildt is one of the most important historians of Nazism. This book, probably his most important so far though the others are, too, is about the 300 or so young men (only one woman among them) who formed the single most important group you've never heard of: the people who made Nazism into what it was.
Soon after the book was published in German I wrote a longish review of it for Yad Vashem Studies, an important journal even if I'm biased in saying so. Apparently I wrote the review in Hebrew (YVS is bi-lingual), so the English review is a translation. Still, it's 14 pages, not 592, so if I can't talk you into reading Wildt's book you might be interested in my summary of it. (The top of the first page is in Hebrew but the article is in English).