I'm surprised no one knew this...
Anyways, I figured it out. The path for the file that holds all the default headers, footers, cover pages, equations, page numbers, table of contents, tables, text boxes, and watermarks is:
C:\Documents and Settings\[username]\Application Data\Microsoft\Document Building Blocks\1033\Building Blocks.dotx
You can customize what is in this file within word by going into the "Building Blocks Organizer" inside of Word 2007. To do this, right click on any object within a gallery, and select "Organize and Delete...".
Once you have finished customizing what you want to display for the users in each gallery, copy your Building Blocks.dotx to a network share, and fashion a script to push it down.
Cheers.