The August 2010 update to iWork lets you export a Pages word processing document to ePub format. That means you can add it to your iTunes library and synchronize it to iBooks on your iPhone, iPad, or iPod touch.
This document provides a step-by-step guide to creating those ePub files and managing them. You'll also see the differences in the various formats: this document is downloadable in Pages, PDF, and ePub formats.
Register and login on northcountryconsulting.com and use the Downloads links at the left of most pages.