In the popular science arena, we occasionally (and in the case of evolution vs creationism, frequently) debate just how likely it is that those who aren't trained scientists can competently evaluate an area of professional science. I love Richard Feynman's somewhat idealistic answer, given in his 1966 talk to the National Teachers Association:

"Learn from science that you must doubt the experts. As a matter of fact, I can also define science another way: Science is the belief in the ignorance of experts. "When someone says science teaches such and such, he is using the word incorrectly. Science doesn't teach it; experience teaches it. If they say to you science has shown such and such, you might ask, "How does science show it - how did the scientists find out - how, what, where?" Not science has shown, but this experiment, this effect has shown. And you have as much right as anyone else, upon hearing about the experiments (but we must listen to all the evidence), to judge whether a reusable conclusion has been arrived at."

Note the catch: that you have to listen to all the evidence. Keeping up with all the evidence can be literally a full-time job, and it is a task whose difficulty the layman most often underestimates. This task is made even harder by high school and college science classes that are focused on teaching what scientists have learned, and not on how they learned it. If you approach every science article you read thinking, "how do they really know this is true?", keeping in mind that there may (or may not!) be some assumed background knowledge you're missing, you'll learn to think like a scientist. Feynman quote: The Pleasure of Finding Things Out: The Best Short Works of Richard Feynman, p. 187