Would you consult a building contractor about your medical condition? A chef about how to prepare an airtight legal document? Probably not.
Written sources (in print or on the web) follow the same logic. Knowing the authority of the author, publishing entity, or other source is important for determining whether the information provided is reliable.
Let's say you were writing a paper on terrorism in Pakistan. Use of information found on a United Nations web page is highly likely to be credible. An article in an established source such as a scholarly journal or well-known magazine like U.S. News and World Report is likely to provide facts and opinions that are reasonably accurate.
Check out the following web site:
A quick web search will lead to you informaton, education, and publications of experts or authorities.