Physics4kids
Physics4 Kids: Electrical Field Basics
This resource explains how an electrical field is created and the criteria that determines its' strength. Other topics briefly addressed include capacitors and the work of Michael Faraday.
Concord Consortium
The Concord Consortium: Molecular Workbench: Electric Field Distribution
Adjust the distance between plates in a parallel-plate capacitor in this simulation, and observe the effects on the electric field.