One resource I found myself consulting over and over again was the Intel Architecture Software Development manuals (https://software.intel.com/en-us/articles/intel-sdm). They're huge and obviously a bit dry, but they had about 90% of what I needed to know about x86 memory architecture and interrupts.

I included some other resources I consulted in the README. The OSDev wiki (http://wiki.osdev.org/Main_Page) is also good, although I found some of it to be dated or incorrect.

Good luck on developing your OS. Even though I'm not finished, it's been an extraordinarily valuable and educational process.