Peer review means that a board of scholarly reviewers in the subject area of the journal, review materials they publish for quality of research and adherence to editorial standards of the journal, before articles are accepted for publication. If you use materials from peer-reviewed publications they have been vetted by scholars in your field for quality and importance.
These are some of the key journals in the field of Jewish Studies. It is easier to search for journal articles using the Library's databases but you can also try to find relevant articles by looking in the key journals themselves. You can browse through journals and look at their tables of content online or in print, depending upon their format. With some online journals, you can also try searching for key terms or authors within the publications themselves.