Article III, §1, of the Constitution of the United States provides that "the judicial power of the United States shall be vested in one Supreme Court, and in such inferior courts as the Congress may from time to time ordain and establish." In addition to the Supreme Court, federal courts include Circuit Courts of Appeal (California is in the 9th Circuit) and District Courts (California has Eastern, Central, Northern, and Southern districts).
Sources of primary law:
U.S. Supreme Court cases are reported in United States Reports (U.S.). Three unofficial reporters are West's Supreme Court Reporter (S.Ct. ), Lawyer's Edition (L.Ed.), and United States Law Week (U.S.L.W.). Not all decisions of the Circuit Courts of Appeal and the District Courts (federal trial courts) are published. Of those that are, Circuit Court opinions appear in the Federal Reporter (F, F.2d, and F.3d) and District Court decisions appear in the Federal Supplement (F.Supp. and F.Supp.2d).
Opinions from the United States Supreme Court are readily available in a variety of sources, most of them free.
Before presenting their oral arguments, counsel for both sides will submit a legal brief summarizing the facts of the case as well as the legal reasoning behind their arguments.
Recent briefs for Supreme Court cases are more readily available than those from older cases. See InterLibrary Loan box, below, for requesting briefs to which we don't have access.