In some cases church websites can provide great information for family historians. While today's example is a more famous and historic church, don't let that get in the way of your searching for the website for the church/es your ancestors attended.
I've been thinking about various types of cemeteries lately and came across these great web pages for Christ Church Philadelphia. Look here for a history, map, and information on preservation at the Christ Church burial ground.
This website has even more for genealogists. Collections and Genealogy includes information about their archives, church records, and their online catalog.