FILE db.cache: This file lists the authoritative name servers for the very top domains. It used to be a real pain to get and keep straight, but the utilities that come with bind version 8 have a little program called "dig" that does all the hard work. To get your db.cache file, while connected to the internet, type:

dig . ns>/var/named/db.cache

Since you need to keep this file up to date, I have not included it here - it is so easy to get anyway. I this set on my dns server via cron to run monthly so it stays up to date.