You can find popular sources like news, magazines, and websites via Google, but you always want to check the credibility of a source before including it in your research.
A simple way to evaluate a website is using a skill called lateral reading. Move outside the source and Google it to find out more about it. For example, if I find a source on npr.com but I'm unsure what NPR is, I can Google it to find out on its Wikipedia page that NPR is an American nonprofit media organization.