Primary Sources are different from most resources you may be used to using. Primary sources are written by people who were present at an event, or who lived at the same time. They are rarely impartial or unbiased, practically never scholarly or academically rigorous, and often contradict one another about the causes of an event, or even what really happened. Despite this, primary sources are the heart of history writing. Why?
Primary sources are as close as a historian can get to events that happened in the past. They give insight into what people who experienced an event, or lived during a particular time, thought, felt, believed, saw, or experienced.
The important thing to remember is that no primary source is authoritative; you should, whenever possible, compare several perspectives on the same event or time period. Also remember that primary sources are often as valuable for what they reveal about how people thought about or experienced a historical event, as they are as descriptions of what took place.