Today Apple updated iBooks to version 1.2.1. The update contains a number of important stability and performance improvements. According to Apple, the improvements include:
• Experience fully illustrated books, from children’s picture books to beautifully designed art books, available for download in the iBookstore.
• Organize your books and PDFs into personal Collections. Swipe left or right to jump between Collections.
• Print PDF documents and notes you’ve written in iBooks using AirPrint.
• iBooks now fits more words per page by automatically hyphenating text, available only on iOS 4.2 or later.
You can update by touching the App Store icon and touching on updates or download from here.