I am completing a government assignment, on twenty-eight different cases. At the present, I am using several textbooks, and Encarta, however, does anyone know of any reliable sites that would be helpful and provide additional information?
Thanks!

If you aren't an attorney, Lawyer, Lawyers, Attorney, Attorneys, Law, Legal Information - FindLaw has sections of the site that the general public can use free of charge.

Not free but used by a lot of law school students

LexisNexis Global Home

A lot of states also have case law available online for published cases. Just as one example, in Illinois, it's Welcome to the Official Site of the Illinois Courts. And, the United States Supreme Court also has case law online. It's at
Supreme Court - Opinions

You can also just Google the name of a case and the links for the case law concerning the case might appear in the searches.