American Baptist Historical Society – why the Baptist church is NOT helpful for genealogists
Digital Quaker Collection, housed at Earlham School of Religion
Evangelical Lutheran Church of America Records 1875-1940 on Ancestry.com (subscription)
Friends Historical Library – Swarthmore College
Historical Society of the United Methodist Church – explains where and how to look for the various Methodist churches that have existed through time.
Local Catholic Church & Family History & Genealogical Research Guide – explains types of records to be found and how to locate them.
The Archives of the Episcopal Church – explains records found in the archives, at the parish level and how to find them