Holocaust Museum Houston:

http://www.hmh.org/

United States Holocaust Memorial Museum:

http://www.ushmm.org/

Yad Vashem
(Holocaust museum in Israel)

http://www.yadvashem.org/

Facing History and Ourselves

http://www.facing.org/

Hermann Wygoda's book
In the Shadow of the Swastika
(one of Upstanders featured):

University of Illinois Press

Vladka Meed's book On Both Sides of the Wall
(Upstander who first inspired me in 2010)

Used copies available on Amazon