Before you can start any research on your topic, you must have a background knowledge of it. Books and websites can provide you with that knowledge.
This is important because:
Use specialized dictionaries to identify terms, clarify jargon and otherwise become familiar with the language of geography.
Specialized subject encyclopedias provide an overview of a topic, familiarize the user with issues names and dates associated with it, and identify additional materials published on the topic, such as journal articles.