Information varies in quality, so you need to approach it critically. Different disciplines and sub-fields value different types of information, and what constitutes "good" information often depends on the context and the use to which it will be put. However, the following "hierarchy of evidence" applies in many cases, starting from sources that provide the best quality of information at the top to the least qualified at the bottom:
Published peer-reviewed research (the gold standard)
Accepted standards in the discipline
Authoritative synthesis (e.g. signed encyclopedia article)
"How we done it good" reports (aka research through design)
Single models without analysis
Proposals
Inferences and opinions
Definition
The process in which a new book, article, etc., is submitted by the prospective publisher to experts in the field for critical evaluation prior to publication, a standard procedure in scholarly publishing. Under most conditions, the identity of the reviewers is kept confidential, but the identity of the author(s) is not. The existence and content of a manuscript under review is kept confidential within the offices of the publisher and by the reviewers, and all copies of the manuscript are returned to the publisher at the end of the process. Synonymous with juried review.
From:
How to Tell if a Journal Is Peer Reviewed
If you know the title of a particular journal, there are several ways to discover if it's peer-reviewed.
1. Find the website maintained by the journal's publisher. The description of the journal usually mentions peer review if appropriate. You can also read the instructions for potential authors, which may spell out the review process.
2. Search the Ulrich International Periodicals Directory. Peer-reviewed journals display an icon that resembles a sports referee's shirt 
3. Search the Library and Information Science Source (LISS) database. The information pages for individual journals say whether or not they are peer-reviewed.
