For aid in identifying online databases and other resources in all subject areas, including areas outside of your subject expertise, subject specific Research Guides can be very helpful.
Also, a very useful online library resource for identifying databases by subject is
Library Literature Review Workshop (Humanities)
Do you need to conduct a literature review for your proposal, dissertation, or research article? Are you concerned about how you'll find the best articles, how to keep track of your findings, or ways to improve your search process? This workshop will guide participants through the steps that will help them search the literature to see what research has been done on a particular topic and how best to keep track of what they find along the way. Participants will learn about the different kinds of literature reviews, how to judge which are the more important writings on the topic, as well as what are some of the more specialized sources to check in their specific fields. Best of all, they will learn when they can stop searching!