Introduction to Basic Legal Citation (online ed. 2013), by Peter W. Martin, Cornell Legal Information Institute

https://www.law.cornell.edu/citation/1-100

This guide can be used for both the 4th Edition of the ALWD Citation Manual and the 19th Edition of the Bluebook. -CCE

(See also Citing Legally Blog, http://citeblog.access-to-law.com/.)