Primary Sources are original sources: they were created by someone who participated in or observed an event. They include diaries, letters, newspapers, government documents, photographs, and other manuscripts.
Google is becoming a really great place to find primary sources. The key to finding them is how you construct your search.
You'll always want to add a keyword to the end of your search that will help you find primary sources specifically. Examples of those terms are: "primary sources," documents, archives, correspondence, images, texts, writings, works, etc.
A few example searches:
The battle of thermopylae "primary sources"
The Trojan War documents
You can also add site:.edu to the end of any search in order to make sure you only bring back .edu sites. That can help with weeding out potentially unreliable sites.
The battle of thermopylae documents site:.edu
Secondary Sources are secondhand sources. They were created by historians who drew their information from primary sources. The most typical types of secondary sources are books and academic journal articles.
The Following can help you format and manage your citations in Chicago Style:
Many databases have a "Cite This" button, but always double check your citation list against the appropriate style manual. Using computer tools can save a lot of time, but there can be small errors.