Coverage: Interdisciplinary and offers content across broad areas of study. However, cannot provide a unifies list of all journal, publications, or sources available to the public.
Scope:Probably the greatest variety of formats; everything from published-in-print journal articles to white papers and university websites. See Google Scholar Citations for a getting started with this service. Google Scholar aims to rank documents the way researchers do, weighing the full text of each document, where it was published, who it was written by, as well as how often and how recently it has been cited in other scholarly literature.
Citation Capabilities: Eeasy to use; look for the "cited by" link under each result. However, not reliable.
Quirks: The fact that Google Scholar indexes work from a variety of sources (patents to conference papers to websites) can be an advantage or disadvantage. The results are often non-existant, duplicated, or irrelevant.
See how to set up a profile to track citations to your work in Google Scholar