Plagiarism is the copying or close imitation of information from a published source.
Consider...
If you cannot determine the credibility of the information you are using, especially from a website, it's best not to use it to factually support your argument. Using biased or inaccurate information in your paper can negatively impact your grade.
Evaluating Information Sources: What Is A Peer-Reviewed Article?
This page thoroughly takes you through peer-review and refereed academic journals for you research
The Peer Review Process