Read through your course assignment.  What type or types of resources do you need?  By determining this, you will know where you will need to search to find those resources.  View the example below to see what sources are needed for this assignment.
The two videos will further assist you in understanding what resources to use.
Review your current research assignment and record what type of resources you will need to find.

Although this video talks about education resources, you can learn the basic reasons that you might use a book or articles, or both.

Many professors will require you to use peer-reviewed articles.  This video will show you how to identify them when you are researching.  For more information, you can also use the link below the video.