A short list, deliberately. Each of these was chosen because it's either the canonical source on its topic or the resource most people in the field actually recommend — not because it's the only thing that exists on the subject.
asic-world.com/verilog/veritut.html
The most complete free Verilog tutorial available online, covering syntax, a full language quick reference, testbenches, and finite state machines in more depth than a crash course can. Good next stop once you want more than this course covers, especially for the reference-manual style sections.
Written by Russell Merrick (FPGA engineer, author of Getting Started with FPGAs). Strongly practical and FPGA-oriented — real modules like UART, FIFOs, and shift registers, with an emphasis on what actually happens when you put a design on real hardware rather than just simulate it.
Not a tutorial to read — a problem set to do. Small, focused circuit design exercises with instant automated feedback (your Verilog is simulated against reference test vectors). This is the best way to build muscle memory for everything in Lessons 2–5 once you've read them; work through the "Verilog Language," "Circuits," and "Sequential Logic" categories in roughly that order.
chipverify.com/tutorials/verilog
Clear, concise, example-driven reference pages — useful as a quick lookup when you've forgotten exact syntax for something (e.g. "how do I declare a 2D array of registers again?").
Clifford E. Cummings, Sunburst Design — PDF (MIT-hosted copy)
The canonical paper behind Lesson 4's blocking/non-blocking rule and Lesson 8's "don't drive one signal from two always blocks" guideline. Written for working engineers, not students, but very readable — worth reading in full once Lesson 4 has given you the vocabulary to follow it.
Russell Merrick's channel — short, focused, project-based videos that pair with the written Nandland tutorials above. Good if you learn better by watching someone build something on real FPGA hardware than by reading prose.
youtube.com/c/nesoacademy — look for their Verilog HDL lecture playlist.
One of the most-watched channels for digital logic and computer engineering fundamentals generally. Their Verilog lectures lean theory-and-exam-style (matches a university course's framing well) rather than project-based — a good complement to Nandland's hands-on approach.
Every external link referenced inline in a specific lesson, gathered here for convenience.