Actually... the best way to get files to the iPod Touch without leaving wifi on and sending things over-the-air is to use the iPhone Tunnel Suite. Google it and you can d/l it. Basically this software package creates a tunnel via the USB connection and then use WinSCP to send files to the Touch via a nice GUI or you can use PuTTY to "tweak" you system at the command prompt level. This method does require a jail-broken Touch, but it's actually quite easy to "own" your Touch. To actually view books, the Touch is actually perfect for PDF's, what with the whole App Store online and lots of juicy-cool packages available. The one I use is "Files." This particular piece of software lets you set bookmarks within PDF's and you can still utilize the landscape mode of viewing without any issues (I think it hooks into Safari and hides that fact, but the bookmark feature definitely sold me!). If you want a free way, simply use Cydia and download the "file://" fix for Safari so you can view PDF's natively in Safari (or any other format the Touch supports.) There is also a eBook app out, though I have no experience with it yet.
Have fun with the Touch, it's a worthwhile investment!