Imagesource: http://www.compatt.com/

If YouTube videos such as those from EEVBlog or Ben Eater float into the inquisitive mind more like small gentle feathers, this thing comes across more like an anvil from a 10m drop. 💥

The United States Navy Electricity & Electronics Training Series is one of the most concentrated collections of electrics and electronics knowledge we have found in a long time. 

James M Patterson is responsible for the version online, and currently provides 24 different modules. Energy, voltage, current, conductors, motors, waves, microwaves, radio, radar, computing up to fiber optics … all topics are discussed in very much detail.

The individual modules are available as PDF files. And for those who either don't have a job, or are already retired, the course provides the concentrated basic knowledge for electrics and electronics.

Free of charge!