Reference encyclopedias, dictionaries, and handbooks provide synoptic articles that can help you quickly learn about areas of inquiry new to you. Additionally -- and this is where they become powerful tools -- they include brief bibliographies written by experts. It's like being given a reading list of the most important works by an expert in the field.
There are many more in the collections. Just search the keyword 'Japan' then, under 'Collections' on the right, narrow to 'Reference Materials.'