When I get started on a research project, the most difficulty I have is figuring out under which key terms my specific topic is categorized under. That's where Google's Wonder Wheel helps me (and Wikipedia, but that's a shameful secret), I start out with some basic search term and it helps me branch out to several new (but similar) key terms. As an example, here's a search term for "plastic safety." Click around and see how the wonder wheel provides you with new key terms: http://www.google.com/search?hl=en&tbo=1&tbs=ww%3A1&q=plastic+safety&btnG=Search