Circuit Sage
- http://www.circuitsage.com/
- Analog and RF circuit design resources. An extensive array of links and information relating to various aspects of circuit design.
Electricity Tutorial
- http://www.swansontec.com/set.htm
- This is a basic introduction to the concepts of charge, voltage, and current. Discusses Coulomb's Law, Ohm's Law, and power. Includes graphics and animations.