Most databases allow you to limit the search to peer-reviewed journals.Just select "peer review" before conducting the search. For example in EBSCO databases:
In ProQuest databases:
You should always double-check whether an article is peer-reviewed by considering its characteristics, especially:
In some databases, users may need to conduct a search first and then are given the option of limiting to peer-reviewed journals on the results page.
It is possible to check whether a journal is peer-reviewed or not in Ulrich's Periodicals Directory.
Ulrich's is available online from the Kresge Library website. Do a search for a journal, and look for the little referee icon before the title of the journal:
If it is there, the journal is peer-reviewed.
To find out whether a journal is peer-reviewed, you can also check their editional policy. Most reputable journals lay it out in each issue, or on their website.