Is this possible to link the value to a database in Apple's iWork suite? For example, I would like to make a Pages document that has a value that's linked to the company information and Keynotes and Numbers as well. So, when our company information changes, all the reference value can be changed. Is this possible to do? If not, does any office suite have this ability?
In any program to find out what fields/data can be inserted at a given point look for the menu item "Insert" if there is one you will see under that menu diffent types of data that can be inserted.  I pages you can "Insert" any of the information from the Addressbook.  In numbers it is much more limited.

AppleScript is most probley to best solution for other data and the apps you ask about.

Better app's for this sort of thing are OpenOffice and MS-Office.