I've moved your post to the InDesign EPUB forum.
What version of InDesign are you using and are you aiming for relfowable or fixed layout epub?
Bob, thanks for moving! (Even though i put it into the other forum consciously, because i thought my question about automatically aligned images also applied to non-Epub uses. Anyway!)
I am using the newest InDesign CC. Honestly i haven't thought about reflowable vs. fixed layout. It is a technical manual with lots of screenshots and no design specialties. Perhaps fixed layout is enough.
Creating ePubs (fixed and reflowable text) and other digital formats from InDesign is not intuitive, and for more than very simple books, has a steep learning curve. There are several books and online tutorials which you’ll find useful. For example:
And obviously you can get help with particular issues from the folks on this helpful forum.
Derek, thanks for detailed links!