<Names of Both Parties>, <Reporter Volume Number> <Specific Reporter in which Case Reported> <First Page of Case> (Date of Decision).
Example: the case Roe v. Wade would be cited:
Roe v. Wade, 410 U.S. 113 (1973).
Here's what it means:
410 = Volume 410 of the
U.S. = United States Reports
113 = case begins on page 113
1973 = date of the case decision
Additional Examples:
United States v. Virginia, 518 U.S. 515 (1996).
Loewen v. Turnipseed, 488 F. Supp. 1138 (N.D. Miss. 1980).
<Case Name>, [year of report] <abbreviation of report> <first page> (Can.)
Example:
Chase v. Campbell, [1962] S.C.R. 425 (Can.)
<Case Number>, <Names of the Parties> official reports of the court year of decision