Introduction to Matter, Energy, and Direct Current

A clear continuing-education course that walks you through electrical safety, circuits, and the core ideas behind how electricity works. A friendly starting point for beginners and anyone refreshing the fundamentals.

TLC

A thorough grounding in electrical theory, from atomic structure and Ohm's law to DC circuits and batteries. Built as operator training, it explains each concept with worked examples and clear diagrams.

U.S. Department of Energy

An accessible reader on how energy moves and changes form, with electricity at the center. Short chapters and clear illustrations make it a gentle entry point for newcomers.

Core Knowledge