Follow the money! News can be spun or slanted to suit the organization that owns the news agency (corporate bias) or to suit the organizations that provide money to the news agency (usually through advertising; hence, advertising bias).
World-Newspapers.com is a site that provides brief descriptions of newspapers from countries around the world.
Cultural bias is the idea that news is filtered or slanted based on the journalist's own cultural ideas. Another related term is "ethnocentrism," or judging other cultures by the yardstick of one's own culture.
In this Google Book preview, Herbert Gans outlines an example of cultural bias in American news media of the 1970s:
This story from National Public Radio highlights an example of access bias -- the idea that news reporting is biased because reporters can't get all sides of the story.
Sensationalism is when a story is embellished or over-represented in order to increase viewership or readership.
This column published by CBSNews provides an example of sensationalism surrounding the swine flu outbreak of 2009: Did We Overreact to Swine Flu Threat?