Shouldn't there be a volume control bar on my player screen? There isn't. How do I adjust the volume of the book I downloaded?
Most devices have hardware buttons on the side of the device to adjust the volume.
I understand from your email that you have an iPod Touch device which does not have volume buttons on the side of the device. If Apple has started to ship new iPod Touch models without volume buttons on the side we will look at adding software buttons to adjust the volume in a future release of the iPhone, iPad, and iPod Touch player.