The iPad supports the ePub format, and you can load these books simply by e-mailing them to yourself. Apple's iBooks app is your portal to reading and buying eBooks on the iPad-and it includes a section with a few free books. But don't forget, just like iTunes and the iPod can import and play music downloaded elsewhere, the iTunes and the iPad can import and display books downloaded elsewhere. And keep in mind, iPad only supports ePub (with or without DRM).
Your local library may be a great source for free ePub checkouts. Also, Project Gutenberg has 30,000 free ePub books you can download, all of which have fallen out of copyright.
There's lots of good stuff in this collection if you read classics, and the project even has an
RSS list for new arrivals.
If you want to convert PDFs and other DRM-free formats to ePub, you can use Calibre.
"iPad Tips and Tricks : Import Free Books "
Reference : top-ipad-video-converter.com