Librarians and Archivists often curate lists of databases by subject as part of their collection practice and to help researchers discover relevant materials.
It's best to start with guides specific to Emory, but for some topics you can search the larger library landscape for suggestions based on geography or topic.
To find non-Emory guides search via google by keyword and the word libguide. You can often get quite specific and search for types of documents or archives. Here are some sample searches:
Search Portals
Gale Videos
Adam Matthew Videos
Readex Videos
ProQuest Videos