Right, so...I read over the things Lissa disccused on SSI, but I have another question that I don't think was answered in her summary.

So, I make this text file and what do I do with it? Do I only insert it into one page that has the menu and it'll go through every single one? Or do I have to include it in every single page that has a menu?

Oy, someone please answer this question...I have a huge website to make for a friend and this would help a lot.

You have to put this code:
<!--#include file="yourfilename.txt" -->

Into any page you want your menu to show up. Your text file just hangs around in your directory and you don't have to do anything with it, really, because the code above will stick your menu on your page (if that made sense?).