How do I save my place in an audio book just as you can with a paper based

I've recently bought a few audio books from the i Tunes store, but when I came to listen to them, I wanted to pause the listening of the book and listen again another day. I looked for a way to 'bookmark' where I'm up to in the audio book so that i Tunes would remember where I last left off and start again at that point. So far I've been unable to find out how to do this and have had to search around for ages to find the right spot. This is very frustrating, because although the audio book is divided into sections, they are very long - a couple of hours so its a bit inconvenient if you're wanting to go do something different and you've not reached the end of a section. Also, I can't get i Tunes to even remember which section I last listened to.
PLEASE can someone help me? Thanks.

Powerbook G4 Mac OS X (10.4.8) Old but reliable power book