Look up the name of the newspaper or magazine via Google, Wikipedia to learn more about the publication. For example, how wide is its readership? How long has it been published? Who owns the publication? Does the publication have a clear ideological position (left or right leaning, pro-government, etc.)?
Media Ownership Monitor is a reliable source that offers information on the media in selected locations, including some Latin American countries (Argentina, Brazil, Colombia, Mexico, and Peru).