Westminster Shorter Catechism.
The Shoter Catechism read by William Hill, Jr. (download zip file).
How Did We Get the Westminster Shorter Catechism?, by Brian Cosby.
A document to help guide you in memorizing the Shorter Catechism in 52 weeks.
BOOKS
Bible Truth Explored: Searching the Scriptures with the Shorter Catechism, by Murdo Macleod (Reformation Scotland).
Glorifying and Enjoying God: 52 Devotions through the Westminster Shorter Catechism, by Boekestein, Cruse, Miller (RHB).
Shorter Catechism Devotions: Timeless Truths for Today, by Robert D. Cathcart.
Training Hearts, Teaching Minds: Family Devotions Based on the Shorter Catechism, by Starr Meade (P&R).
Bible Truth Explored: Searching the Scriptures with the Shorter Catechism, by Murdo A. N. Macleod (Reformation Scotland).
An Explication of the Shorter Catechism: With an Introduction to John Thomson and His Work, by John Tomson (Westminster Seminary Press).
Shorter Catechism Project. Links to various online commentaries (including Thomas Watson, John Flavel, etc.).
AUDIO/VIDEO
(video) Rev. Jonathan Mattull teaching on the Westminister Shorter Catechism.
(video teaching) Rob McCurley teaching on the Westminister Shorter Catechism. For audio only click here.
Jim Cassidy teaching on the Shorter Catechism Qs. 1-38 and Qs. 39-107. See also Jim’s Study Guide.
James La Belle teaching on the Shorter Catechism.
Gavin Beers preaching on the Shorter Catechism.
Bob Burridge teaching on the Shorter Catechism.
Stuart Olyott teaching on the Shorter Catechism (audio not the best).
CARDS
The Westminster Assembly The Shorter Catechism Deck, by Grange Press.