Including an online guide or printed list of places where patrons can explore more information would be a great addition to this display. Most Holocaust museums/memorials have places on their websites with online educational materials.
If your local community is hosting any events, you can include information about that as well. Relationships can be built starting with just promoting another non-profit's events.
Other resources:
The United States Holocaust Memorial Museum
Yad Vashem - World Holocaust Remembrance Center
Holocaust Memorial Day Trust (UK)
Florida Holocaust Museum
Auschwitz-Berkenau Memorial and Museum
