Reference resources are a great way to get started with your research. They can help you gather fast facts about a topic, focus your argument, and find lists of further readings written by experts in the field. Use the indexes and tables of contents to understand what you will find in each and go from there.
Many of the encyclopedias listed below are accessible via Credo Reference. You can do a more general (not publication-specific) search in the Credo Reference database:
The following are good for getting an overview of countries.