The Holocaust actually began as soon as Hitler came into power as he began putting restrictions on Jews. Jews had to turn in their radios, bicycles, and move into ghettos which the Nazis established to control information and Jewish movement within the country. If you reference Kristallnacht or Night of Broken Glass, open attacks on Jews were approved by the Nazis. Interesting is a difficult word to interpret here as much of what the Nazis did was systematic extermination of a whole people. One of the oddest examples of that is the Theresienstadt concentration camp which was a show camp for visitors. Jewish musicians would play, artists would paint, teachers would teach so that all looked normal. When the Red Cross came back to again view the camp, all looked the same. What they didn't notice was that none of the people were the same. The previous residents had been sent to their deaths while new residents took their place. The whole odd system of how the Germans kept track of every Jew, registered every person sent to the camps, and kept those records so that even now, people can look up what happened to relatives using the Germans own records is astounding as they were often convicted of war crimes using their own records against them. Some of the details are gruesome, so I hope this is what you are looking for in your search.