More links.

1) This link i keep visiting ONLY because of the contents.

http://www.hardwaresecrets.com

2) Some Links on grub

http://www.troubleshooters.com/linux/grub/grub.htm

http://www.linuxjournal.com/article/4622
http://www.gnu.org/software/grub/manual/grub.html

3) PC architecture
http://www.karbosguide.com/