Not everything you find is a great resource. Sometimes the article you think will be perfect doesn't really help. Sometimes the information you find is just unreliable.
The web is full of unreliable information, but that stuff can even find its way into books, magazines, newspapers, etc. Ever see someone believe an Onion article?
There are a few things you can do to make sure your resources are the best for your research. One is to try to find scholarly and/or peer-reviewed articles, and the other is to apply the CRAAP test to your resources.
C: Currency: The timeliness of the information. When was the information published or posted?
R: Relevance: Is the information directly related to your topic?
A: Authority: The source of the information. What are the author's credentials?
A: Accuracy: The reliability and correctness of the content. Where does the information come from?
P: Purpose: The reason the information exists. What biases are involved? Is the information fact, opinion or propaganda?
Use this link to print a copy of the C.R.A.A.P. Test created by the librarians at Cal State Chico.
When an assignment calls for scholarly sources, typically that means academic books and articles from periodicals. A quick rule of thumb for telling whether a source is scholarly is to look for a works cited list or bibliography in which the author refers to the work of other researchers. Also, check Anatomy of a Scholarly Article from the North Carolina State University Libraries.
Some scholarly articles are called peer-reviewed as they are critically evaluated for originality, quality of research, and clarity of presentation by the author's peers, i.e., other experts who do research in the same field.
See this video from UW for an overview:
If you aren't sure whether or not the group that publishes a journal is "scholarly" or not (for instance, maybe you've never heard of the Modern Language Association and so don't know that it is the association of college and university English professors), you can look at the section in the journal where the list of editors is given. Scholarly journals usually list not only the editors' names but also their academic credentials (what degrees they have earned, or where they are a professor). If a journal offers no such list, then chances are it is NOT a scholarly journal because if it were, it would list the names and credentials of its scholars. You can find this information by looking at a hard copy of the journal or by visiting the journal's webpage and searching for its list of editors.
If you run across a random article on the Internet, you need to ask at least two questions: