1) Learn which news sources tend to be the most reliable over time. Information there is more likely to be accurate than information from unknown sources.
2) Information based on hard facts observed in the real world is more likely to be accurate than opinions, interpretations, estimates, or forecasts.
3) Distrust anything that is very strident in a particular direction. The more slanted a piece, the less likely it is to be accurate. Good science and good journalism both call for an exploration of two or more sides to an issue. In order to make a sound argument, you must address and disprove the main points in favor of the opposing viewpoint or hypothesis.
4) Learn to identify logical fallacies. Most inaccurate material will contain one or more of these. The more you see in a piece, the less reliable it is.
5) Understand basic principles of logical thinking, scientific method, history, geography, social and hard sciences. Compare new material to previous material. Data points that conflict established knowledge are less likely to be accurate -- but bear in mind that sometimes knowledge does evolve.
6) Collate input from many different sources, from different ethnic, economic, and political backgrounds. Triangulate the scope of an issue by absorbing as much information about it as possible. Identify the main points of contention. Seek hard facts that support or undermine them. Which are more compelling and convincing? Why? Look for congruent areas where people who disagree about some things agree on a certain point; that point is more likely to be true. Identify areas where not enough is known yet to make a firm decision, and seek more research. Identify and discard clearly unreliable information (citations that don't pan out, logical fallacies, etc.). Sift what remains for the most solid bits and begin to assemble your stance from those.
I do this all the time with news in general, but particularly in my areas of interest. This is one reason why I often batch items together that relate to different aspects of the same issue. It's also why I watch for good counterpoint articles, so I'm not seeing -- or sharing -- only one side. And it's why I complain about people burying good arguments in left/right straw man flame fests.