Systems programming

IMHO nice resources:

• JacobSorber on YouTube: Great ~10 minute introductory videos on C, systems programming etc.
• The Cherno's C++ playlist on YouTube: Great tour of C++.
• Stroustrup: A Tour of C++ (Third edition): Great first book for C++, IMHO required to read something like this before any substantial C++ programming to prevent pain.
• Driving Compilers: Medium-sized explanation of a C compiler, covers driver, preprocessor, compiler, linker and loader.
• Expert C Programming: Deep C Secrets: Great second book for C. Funny and very readable.
• CppCon: “Curiously Recurring C++ Bugs at Facebook”: Lists favorite C++ footguns and how to avoid them.
• Serebryany: Sanitize, Fuzz and Harder Your C++ Code: How to get serious with testing when it counts.
• The Linux Programming Interface: The book for programming on top of linux.

See also matklad's Fantastic Learning Resources