African American Newspapers Forum
ProQuest Newspapers Search Tips
In an earlier post I mentioned the (then) upcoming webinar by Pamela Weisberger on newspaper research hosted by the Southern California Genealogical Society (SCGS).
She provided a ton of information (much of it covering foreign papers) and is a very knowledgeable and dependable source for newspaper research.
One of the resources that caught my attention was this one detailing the various search terms for ProQuest papers.