Start Basic! One of the best places to start is Academic Search Premier. This will find both scholarly journals and popular newsstand magazine articles on almost any subject.
Other science databases you might want to try include:
Iowa State University is a member of the Digital Commons Network - the collection of institutions making use of the bepress Digital Repository platform. This resource provides a way for anybody to easily find Open Access materials (papers, articles, theses, etc.) that all member institutions have provided.