Even if you already know quite a bit about your subject, start with a general search in news resources like the New York Times. You might also search an encyclopedia or Wikipedia entry for an essay on your subject. Once you have gathered some general information, you might search popular publications such as Nature or Science for articles that dig a little deeper. The scholarly and peer-reviewed articles that can be very technical and specific are found in science-specific databases such as Science Direct, Springer, Web of Science, and IEEE (to name a few).
The New York Times is a good place to start because there you will find current stories that mention the names of experts and organizations that are authorities on your subject. An added bonus of searching the New York Times is that you will occasionally find links to scholarly publications like in this story about the woman who doesn't feel pain which links out to the actual study the Times story is based on.