Any leftover of the past can be considered a source. It might be a document, and we often think of history as a discipline based on the interpretation of written texts. But it might also be a building, a piece of art or an ephemeral object – a train ticket, say, or perhaps a pair of shoes. [source]
Searching for Historical Sources online involves more than just a google search.
Try and think about what type of publication you need to access to find value in your searches
Your Sherlock Holmes skills will come in handy as you ferret through "general resources" created for general consumption and drill down to sources closer to the actual event which provide you with unbiased evidence of the event, person or time in history.
If you are a Humanities student, make sure that you have library membership to the following libraries. Most memberships are processed online and you get a card sent in the mail.
Using Archival Evidence to guide your research.