So I have sent my lovely book off to be typeset and laid out by a pro, and have spent many weeks looking at the inside of books, none of which so far have had any kind of 'standard' layout as far as I can see - they do vary enormously.
But - getting the font right and the chapter headings of your book looking decent is essential. The font says so much about whether your book is literary or commercial, modern or old-fashioned. The chapter headings give a flavour of the type of book the reader can expect.
|Illustrated Chapter Heading|
Also bear in mind that designers like design - i.e. they might want to squeeze as many fancy ideas for fonts as possible - curlicued chapter-headings, drop-capitals, twiddly numbers, and the end result can be distracting rather than enhancing for the reader.
From this I saw that too much illustration and design, and the book ends up looking like a children's or young adult novel. Too little and it looks like it has not been designed at all.
If you don't know what you want until you see it (that was me, I'm afraid) then this site has a selection of 50 templates ready for use along with the instructions about how to format your document in Word. Well worth a look even if you are asking a designer to format your book.