We are big fans of tools in the browser for education. You have a consistent environment maintained by someone else, you don’t have to install anything, and you can work from any computer you happen to find yourself. The HDLBits site has a great set of Verilog “exams” that would be a big help to anyone trying to learn or brush up on their Verilog skills.
The site offers a range of topics that go from the silly (output a constant 1 or 0) to full-blown state machines and testbenches. The site isn’t tutorial in nature, instead it offers a problem, an optional hint, and an editing window with some code already in place. You add your code and hit submit. Behind the scenes, the site runs Intel Quartus and Modelsim to test your work. It will either show you the results or tell you that you failed.