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:
There are numerous titles that provide an overview and background information on educational administration and leadership. This list of encyclopedias is a small selection. In addition to a broad overview and seminal scholarship on a given topic, encyclopedias can provide useful perspectives on how topics might be organized and/or keywords/phrases to use in more in-depth searching.