This is easy.
Turn on MSNBC today. Watch what they are covering.
Then turn on Fox News. Watch what they are covering.
I bet it's not the same thing. Nor is it being covered the same way.
On MSNBC this morning, they were covering President Obama live talking at and to Planned Parenthood's National Conference. He was talking about women controlling their own health care decisions.
At the very same time, on Fox News, there was a panel discussion about President Obama's investment in electric cars and whether this is an appropriate use of taxpayer resources. No live coverage of the president nor discussions about how Planned Parenthood actually does far more than provide abortions.
This form of bias--what to cover and what not to cover, as well as how to cover it--is the most significant source of bias in the news today.
When it comes to crime we see the same thing--some forms of crime are coverered and others are ignored. Only MSNBC and Fox News typically cover and ignore the same kinds of crimes.