Topics discussed: x86/x64, ARM/ARM64, MIPS, Java/JVM.
Compiled versions can be found here: https://beginners.re/
See also the ChangeLog for the latest changes.
Want to contribute in some way? Read here. Do not worry to bother me while writing me about any petty mistakes you found, even if you are not very confident. I'm writing for beginners, after all, so beginners' opinions and comments are crucial for my job.
Want to translate this book into some other language? Read here.