These resources should help you in citing legal sources:
ALWD Citation Manual: A Professional System of Citation, 4th ed. by the Association of Legal Writing Directors. The manual is available for in-library use and is at the Ready Reference area behind the Reference Desk at Speed Library (top floor). Several copies are available at MC Law Library.
The Bluebook: A Uniform System of Citation, 19th ed. Compiled by the editors of Columbia Law Review, Harvard Law Review, University of Pennsylvania Law Review and Yale Law Journal. The Bluebook is available for in-library use and is at the Ready Reference area behind the Reference Desk at Speed Library (top floor). Several copies are available at MC Law Library.
This online site provided by Cornell Law School may also be useful: An Introduction to Basic Legal Citation.
You can see Speed Library's complete citation guide for other citation styles here.