Jewish Encyclopedia: Manasseh 
Overview of the son of Joseph from the traditional Jewish perspective, including rabbinic commentary.
http://www.jewishencyclopedia.com/view.jsp?artid=124&letter=MCatholic Encyclopedia: Manasses
Commentary on the son of Joseph from the traditional Catholic perspective.
http://www.newadvent.org/cathen/09583c.htm
Manasseh
Profile of the son of Joseph from a joint Lutheran and Catholic bible study project.
http://www.aboutbibleprophecy.com/p132.htm
Efraim and Menashe
A rabbinic reinterpretation of the favoritism Jacob shows his grandsons.
http://www.midreshetharova.org.il/onlinetorah/archive/breishit/vayechi5761.php
