Writing Protected Mode x86 OSes?

windex asks: "I've been looking recently for information on writing a OS (OS == kernel) from scratch, mainly as a personal science project. I've been looking for information on how to do this, however the only real information I've found is on developer.intel.com and its mostly in Intel-ese, not English. Does anyone know of a good place to start getting the basics of the x86 architecture?" There are probably plenty of x86 ASM books out there that can serve as a good reference for this project, but what about references that discuss writing the portions of the basic OS (memory management in particular)? If you find this question interesting, you might want to check out a previous topic we've done on multiplatform device drivers.