Spent the better part of the day trying to get kindle to seperate pages properly. It is a word doc with graphics. One graphic per page (no text) kindle insists on putting two images/pages on a page for some but not other pages??
Part of that is going to be the size of the graphics. Kindle "reflows" everything to fit as much on the screen at once as it can. So smaller graphics will fit multiple ones per screen. Larger graphics will only be able to fit one. If you really want one graphic per screen, then insert some page breaks in between the graphics (not just carriage returns), then do your conversion. Pretty sure that will work, though I don't do Word to Kindle conversions much at all.
HTML is the best way to ensure control over what is going on but I doubt you're wanting to go down that road right now
My recollection was that in the old days one would run the material through Calibre for the final formatting for Kindle (MOBI?). On the other hand, for personal use, I've had some luck emailing PDFs to my Kindle.