A peer reviewed journal is one in which articles are submitted to researchers who are experts in the field and its content and references are evaluated for accuracy before they are published.
Peer-reviewed journals will have the following:
The Study Design 101 tutorial help you understand the different kinds of studies and each studies strengths and weaknesses.
Before using a web site look at the URL (web address) to identify the producer of the web site, and its purpose.
Look at the last final syllable in the domain name to evaluate who produced the site:
.gov = Government agency
.net = Internet Service Provider
.com = Commercial site
.edu = Higher education
.mil= Military site
.~ = ("tilde") Personal
.org = Organization