Richard Haskell is still writing accessible introductory books for Verilog and VHDL. His new books look pretty good, but they came along a bit too late to help me this time.
[0] https://skilldrick.github.io/easy6502/
[1] https://www.amazon.com/Apple-II-6502-assembly-language-tutor...
[2] https://archive.org/details/Apple_II_6502_Assembly_Language_...