How did the Nazis persecute the Jews?

They encouraged the boycotting and destruction of Jewish-owned businesses. They passed laws prohibiting Jews from engaging in large areas of German professional life. They forced Jews into ghettos and concentration camps, where many died of disease or direct extermination.

Jews were forced to wear the David Star

(Source: http://isurvived.org/Holocaust-definition.html)

They persecuted Jews in every way they possibly could. What started out as harassment turned into vicious treatment by the media and became an all-out hate campaign. Unfair laws were then passed, making it increasingly difficult and later impossible for Jewish people to live normal lives or even earn a living. Then began the forced deportations to ghettos, and later, death camps in the East. In between all of this were untold murder, imprisonment, torture, theft and destruction of property.

One of the most noticeable and dramatic action taken against the Jewish citizens of Germany and Austria during that time (that for many observers was the first hint of what was yet to come) was the nationwide pogrom in the night of Nov. 9-10, 1938 known as the Kristallnacht or "The Night of Broken Glass" pogrom.

The Night of Broken Glass (9-10 November 1938)
(Source: http://isurvived.org/Holocaust-definition.html)

During the War years (1939-1945) that had followed, the Jewish Persecutory Program developed and transformed into a genocidal Persecutory and Victimization Program --the Holocaust, with a machinery set in place primarily for the complete destruction of the entire European Jewry.

Jews are transported form Kovno Ghetto to Auschwitz Concentration Camp

The Einsatzgruppen or "special action groups" or "killing squads" followed the German Army into the Soviet union in June, 1941, where almost 3,5 million Jews lived. As the German Army advanced they rounded up all the Jews and shot them. Almost 2 million Jews were killed in this way. Not only the Jews were rounded up, but as well as communists, Roma and Santi (gypsies). The Einsatzgruppen consisted out off ordinary people who joined. But in 1941 the Nazis decided that the Einsatzgruppen was inefficient and to slow. They created instead the so called "death camps" where people could be gassed in large numbers. Some of these camps were - Auschwitz-Birkenau, Treblinks, etc.

Most of these death camps are situated in Poland, away from the German civiliance who were ignorent about the killings.

Nazi Concentration and Death Camps

(Source: http://www.martinfrost.ws/htmlfiles/holocaust.html)

Action T4 was the name used after WWII for Nazi Germany's eugenics-based "euthanasia" programme during which physicians killed thousands of people who were "judged incurabley sick, by critical medical examination". The programme officially ran from September 1939 until August 1941, but it continued until the end of the Nazi regime in 1945.

(Source: http://wiki.answers.com/ AND http://isurvived.org/Holocaust-definition.html)