Some applications have their own unique preference settings. One of these is iBooks. Flipping pages in iBooks is easy. You tap the left margin to go back a page or tap the right margin to go forward a page. No need to swipe to change pages. If you think about it, most of the time you progress forward through a book. That means your right thumb gets a workout while your left thumb gets lazy. You can set iBooks to flip the page forward no matter what edge you tap. If you need to go back a page, you can still swipe.
Settings > iBooks (under Apps)
Excerpt from my eBook iPad Academy: Tips, Tricks and Clever Techniques