*The Art of Construction; Projects and Principles for Beginning Engineers and Architects by Mario Salvadori (Chicago Review Press)
This is an incredibly engaging and informative beginner's guide to how architecture works and a great opportunity to see science and math applied to real life. It includes simple building projects and experiments to demonstrate architectural princilpes.
*Building Big with David Macaulay (DVD Set from PBS Video) and Building Big (book) by David Macaulay
This series includes individual shows on Bridges, Dams, Domes, Skyscrapers and Tunnels. Your kids will learn lots about the science, history and art of large structures. A few small scenes may be frightening or disturbing to younger or sensitive children.
Roman Arch Blocks (available from Michael Olaf)
The arch is an amazing and very essential aspect of architecture. This block set demonstrates the concept in a fun and memorable way - a great learning activity for preschoolers (and their older siblings!) that they will enjoy again and again.
Unbuilding by David Macaulay
This book, written in 1980, is somewhat painfully outdated since the fall of the World Trade Center, but is nevertheless a fascinating look at the "how" of architecture through a fictional story in which an oil tydcoon from the Middle East purchases the Empire State Building, disassembles it, and relocates it to the Arabian Desert.
NOTE: The Bridge segment of this study (and of the notebook) is particularly conducive to the study of science and math. Make individual pages with illustrated examples of each of the major types of bridges: post-and-beam, suspension, truss, cantilever and cable-stayed.