It would be very helpful if in the case of novels ( and perhaps some other types of book) you provided a dramatis persomae.
Also perhaps in the index a synopsis of each chapter.
Older publications often provided these and they are very helpful to those of us who are doing other things and returning occasionally to the book.
And one more thing. Travel Books !! How about some decent maps ? Rather than the pathetic line drawings normally provided.
Actually travel books aren’t the only culprits in the map department. Field Marshall Slim’s book ‘Defeat into Victory’ suffers badly from not having comprehensive maps particularly now that many of the places named have been changed after Burmese independence.