Free Range’s author James Mealy has a long trajectory in the free diffusion of logic design.
On this site, you can find free books (Logic foundation and Verilog), selected chapters of the course on video, and solutions to the course’s lab exercises.
From the author page :
I started collecting digital design textbooks after arriving at Cal Poly; I was sure that writing books meant having all the books possible on the subject and arranging the information differently. What I found was that I simply didn’t like the approach taken in every digital design textbook I’ve ever read. This led me to take a different approach, which I’ve done in the FreeRange series of courseware. I put more comments regarding the approach on a different page and in the actual textbooks as well.
Free Range – Digital Design and Verilog Modeling
You may also want to check: Free Range VHDL (free book)