With every source you find - regardless of where it comes from - you MUST assess its quality to determine if it is worthy of being included in your research. Generally speaking, academic papers are looking for you to first consult scholarly, peer-reviewed research from reputable publishers.
*Note that you should always follow the instructions given to you by your professor. There are certainly times/places when using other materials have value to your research!
For every resource you find, a good place to start is with the CRAAP test!
When was the resource published?
Is this the most up-to-date information available?
Does this matter for your topic?
Even if it is up-to-date, is the information going to answer your research question?
Is the scope of the material appropriate for your needs?
Is there a listed author(s)?
Can you determine the author(s)' credentials or qualifications to discuss such topics?
Are they citing other experts?
Are both the publication and the publishing company reputable?
Has the resource undergone peer review?
Is the information contained within correct?
Are there any noticeable errors or questionable content?
Why was this information written and made available to you?
Was it written for academic purposes, for interest reading, to sell you something, to influence you? etc.
Is it biased or promoting an agenda?
Predatory publishers, also known as predatory journals, are publications that will accept virtually any article as long as they are paid to do so. The result of this is poor quality scholarship that is made widely available under the guise of having merit. Pay attention to the following warning signs when assessing the quality of a publication.