Reading Primary Sources

I love reading primary sources.
It turns my endeavor of collecting facts about a historical period into an act of intimately studying the lives of people-- their attitudes, assumptions, daily struggles, and most cherished goals. However, it's also important to remember that these sources are direct reflections of their environment, and as such, fall onto the spectrum of unreliable narration.
Here are my favourite tips on how to put your sources in context in order to get the most-- and the most useful-- information you can from them:
Consider the writer. Each of us have unique life stories, but for some reason we seem to assume that people from the past are generic and interchangable. Find out what you can about the writer-- where were they from, what was their social standing, how old were they when they wrote the piece? Did they have any strong political motives?Consider prevailing attitudes. Some abolitionist literature from the 1700s and 1800s is shockingly racist by modern standards*. But compared to more typical attitudes of the time, these sources show progressive views. It's most informative to look at sources by comparing them to contemporary thought than to look at them through a modern lens. Look at background information. Knowing the general environment can help you understand not only references in the images or text, but the events leading up to whatever your sources are recording. This can shape how people reacted to or evaluated events-- records made in an era of unrest and paranoia will have different tone and content than those recorded in a stable environment. Avoid the Historian's Fallacy: Your source had zero knowledge of the future. This sounds obvious, but it's tempting to view the actions of historical figures in light of the outcome, rather than looking at their choices and views in the context of what knowledge they had available. 
Primary sources are great fun, and hopefully any of you writing historical fiction (or using historical periods as a reference for your imagined worlds) will have fun with them.

*This isn't an attempt to excuse racist (or sexist, etc) material, but to explain it and place it in an appropriate perspective.