Start with the Basics like ohms law, resistors, voltage current. Learn the math and equations too.
Schematic Diagrams, Complicated Circuits, Ohm's Law, Kirchhoff's Current Law, Kirchhoff's Voltage Law, Resistors in Series, Resistors in Parallel.
DC Circuits - University of Guelph
Physics Tutorial Menu - Dimensional Analysis, Graphing Oscillating Fns, Torque and Rotational Motion, Simple Harmonic Motion.