Googling is a great way to find archives and digital collections online. However, sometimes these collections are hidden several levels deep and aren't readily unearthed by Google.
Here are questions to help locate a digital collection or archive:
Libraries rock. Try this fun Google search to learn if librarians at another university created a research guide on your topic: topic site:.edu inurl:lib
This search is telling Google to look for your topic on library websites (inurl:lib) at universities (site:.edu).
For example, I'm researching death rituals. Here's a search I can try in Google: death rituals site:.edu inurl:lib. And from it, I discover a class guide at the University of Minnesota that, while it concentrates on current death and dying issues, also indicates resources for traditional rituals.