Below are links to databases and websites containing a huge quantity of primary sources of all types that are available online that might be useful for your research for this class. Choosing where to search can be overwhelming - start by thinking about what type of source you're looking for, then read the description below each link.
At the bottom of this list are examples of printed volumes in Randall Library's collection containing primary sources (in this case, on the Armenian genocide). There are many more, both in the library collection and via WorldCat that you can borrow using Interlibrary Loan.
Remember, too, that this list is not exhaustive. If you're not finding what you're looking for, please feel free to contact me and I can try to help.