I've commonly heard it said that there is no such thing as unbiased news. Although I don't believe that to be true, catching subtle biases can be tricky. Here are some indicators you can look for the next time you're reading an article or listening to a broadcast.
Here are a few ways news sources give the facts and a false impression, whether intentionally or subconsciously, and thereby misguide their audiences.
When a headline states "someone denies something" the implication is that the someone did the something and is now compounding his misdeeds. On the other hand, when a headline states "someone accuses so-and-so of something" the onus of burden is on the accuser.
The bottom line is that the one who is described as taking action, even neutral action, is almost always seen in a less positive light.
There are two basic patterns in quote order. Beginning with the quote, and ending with the quote.
"blah blah" said john doe, director of something or other
director of something or other, john doe, said "blah blah"
The negative bias cascades downward across the sentence, growing as it proceeds.
When we start with the quote it seems like fact, and the additional information only tempers it slightly. On the other hand, when we end with the quote, we have already seen the additional information and become less credulous.
Often there are a variety of people involved in a newsworthy incident with the same basic opinion. Who gets quoted is often a matter of sensationalism, but just as easily indicate a slant to the story.
Look for positions brought from people with names or titles showing a vested interest in a particular side, and those brought from others, unencumbered by such evident affiliations.
Obviously this is not a comprehensive listing, but it will hopefully get you thinking about bias in the news and how to uncover it.
It should also be apparent that in addition to being useful information for bias detection, it also has the potential to serve as a guide to subtly misguiding others. I don't condone such behavior.