Do you have it split into pages already? Or are you looking for PHP to dynamically select the text and create pages from word-count/length?
Give an example of what you're trying to do (or even an exact article) and we'll try to help you out.
I have a custom pagination thing going on at my personal site. I've written a few articles for PHPBuilder, and I'm working on porting them over to my site as a secondary source, and there are a few that have multiple pages. So I took them, put them in an XML file, and created my own pagination stuff. You can view an example by going here and clicking on "Articles" in the top bar, then select "Read Now" for the article entitled "Simple Remoting". If you scroll down to the bottom, I have a link "Next Page »" which changes to "« Previous Page" when you move on. Something simple, but it works.
