The Big 5 Criteria can help you evaluate your sources for credibility:
News outlets, think tanks, organizations, and individual authors can present information from a particular political perspective. Consider this fact to help determine whether sources are useful for your research.
Check a news outlet's website, usually under About Us or Contact Us, for information about their reporters and authors. For example, USAToday has the USA Today Reporter Index, and the LA Times has an Editorial & Newsroom Contacts. Reading a profile or bio for a reporter or looking at other articles by the author may tell you whether that person favors a particular viewpoint.
If a particular organization is mentioned in an article, learn more about the organization to identify potential biases. Think tanks and other associations usually exist for a reason. Searching news articles about the organization can help you determine their political leaning.
Bias is not always bad, but you must be aware of it. Knowing the perspective of a source helps contextualize the information presented.
In general, websites are hosted in domains that tell you what type of site it is.
Commercial sites want to persuade you to buy something, and organizations may want to persuade you to see an issue from a particular viewpoint.
Useful information can be found on all kinds of sites, but you must consider carefully whether the source is useful for your purpose and for your audience.
Content farms are websites that exist to host ads. They post about popular web searches to try to drive traffic to their sites. They are rarely good sources for research.
Fact checking can help you verify the reliability of a source. The following sites may not have all the answers, but they can help you look into the sources for statements made in U.S. politics.