German Federal Archives Memorial Book – www.bundesarchiv.de/gedenkbuch/
Initiated by Yad Vashem and complied at the German Federal Archives, this is a searchable memorial book for the Victims of the Persecution of Jews under the National Socialist Tyranny in Germany 1933 – 1945

German Genealogy group – www.germangenealogygroup.com/

Leo Baeck Institute – www.lbi.org/
Founded in 1955 to preserve and record the history and culture of German-speaking Jews. Part of the Center for Jewish History.

Meyers Gazeteer – www.meyersgaz.org/
A German gazetteer that compiles every place name in the German Empire (1871-1918). It gives the location, i.e. the state and other jurisdictions, where the civil registry office was and parishes if that town had them. It also gives lots of other information about each place.