This site from NASA offers a general overview of air pressure. Explores the concept through experiments and interactive games, as well as discussion questions.

Investigate air pressure, motion and the forces of air currents using a bendy straw, a balloon and a rubber band.

Try this at-home science experiment to learn about air pressure.

Kids learn by experimenting with science. Project showing how air does have weight and creates air pressure.

Air pressure can be dramatically shown with this simple experiment that only requires an aluminum can, tongs, a 2-3 quart sauce pan and a stove.

This resource provides information and demonstrates the egg in the bottle trick.