https://launchschool.com/books
Intros to Command Line, Git, Ruby, HTTP, SQL, Javascript, and more
https://kremlin.cc/k&r.pdf
The C Programming Language by Brian W. Kernighan and Dennis M. Ritchie
http://cslibrary.stanford.edu/101/EssentialC.pdf
Essential C by Nick Parlante
http://cslibrary.stanford.edu/102/PointersAndMemory.pdf
Pointers and Memory by Nick Parlante
http://cslibrary.stanford.edu//103/LinkedListBasics.pdf
Linked List Basics by Nick Parlante
https://www.worldradiohistory.com/index.htm
A LOT of books, magazines, and historical materials related to electrical engineering, radio, television, and so much more like damn.