Tertiary sources are excellent starting points! They consist of information synthesized from primary and secondary sources. Examples include:
These resources give you succinct overviews of your topic, explain scholarly arguments, point out interesting questions, and refer you to especially key sources.
The following links will take you to large, multidisciplinary digital collections of subject encyclopedias. The Gale Virtual Reference Library is an especially good place to start for research in STHS, as it includes reference works such as Science and Its Times; Encyclopedia of Science, Technology and Ethics; Complete Dictionary of Scientific Biography; Bioethics; and more.