U.S. (Supreme Court) Reports - 1882+, Government Documents Reference
U.S. Supreme Court decisions are reported in:
1. United States Reports
2. Supreme Court Reporter
3. Supreme Court Reports, Lawyers Edition. 1st and 2nd series.
4. Supreme Court Briefs and the Transcripts of Oral Arguments at U.S. Supreme Court Website
U.S. Court of Appeals decisions are reported in:
1. Federal Reporter
U.S District Courts decisions (also U.S. Courts with special jurisdictions, e.g. Tax Court, Claims Court, Customs, etc.) are reported in:
2. Federal Supplement
Federal Judicial Center - education and research agency for the federal court system; organization, history, notable federal trials, etc.
Federal Court Concepts - introduction to the U.S. federal court system: structure of the federal courts, the kinds of cases, how to use in research.