Tackling a new topic?
Try looking for a review article first. Review articles attempt to summarize the state of research on a scientific topic. While lengthy & not generally including the very latest research, review articles can be a great way to start to get a handle on a topic.
Don't overlook the literature cited at the end of the review - the bibliography contains a wealth of information about the key discoveries & main researchers in the field.
Most databases (including BIOSIS Previews, PubMed & Web of Science below) will allow you to limit your search to include only review articles or literature reviews.
For articles describing primary research using scientific methods, written by experts in the field or scientists, try these biomedical, biology and life sciences databases: