play/pause for audiobooks

I have similar situation and questions. I copy .mp3’s from my computer, so it’s not an audible issue. All the help/support, even th manual seems to be about downloading audible/overdrive etc.  What I need to know is how to control the playing of the audiobook, such as in overdrive: bookmarks, pausing, stopping, …  Was able to pause once by more or less randomly pressing buttons, but couldn’t duplicate it. Where can I find this information?