Encyclopedias and other reference sources are good places to find broad overviews on a topic. The SSU library has a number of reference databases that you can search from your computer.
*Wikipedia (yup, Wikipedia) can also be a good source for basic background knowledge. Though I wouldn't use it as a cited source in an academic project, it's a great place to find a broad overview of a topic. A well constructed Wikipedia article will also include references to the sources used and those may be very useful in your research.
If you aren't sure where to start with the library databases, the databases below are good places to start.
Statista consolidates statistical data on over 80,000 topics from more than 22,500 sources, including consumer data, market research, social and cultural statistics, media and advertising data, and more. ***STATISTA DOES NOT WORK WELL IN FIREFOX; PLEASE USE AN ALTERNATE BROWSER***
A background source can be anything that helps you understand your topic and the issues around it. Reference sources are great for background research but other types of sources can be useful too. A news story or article in a popular magazine (online or in print) can give a good overview of an issue. A news story, or film like a documentary can also be a great source for background research.
The Oxford Very Short Introduction series offers brief overviews of topics as well. You can find this collection on the second floor of the library across from the information/checkout desk.