Let's face it, the research and writing are the fun parts of producing a book, and then there's the other stuff that is much less enjoyable but vital. Here are a few thoughts:
1. Editing. I've mentioned a writer's "darlings" in a previous post, and in some ways the whole book is the author's darling - it's your idea and you have slaved over the stories, the translation of science into an accessible and exciting form, and you've crafted the words, the phrases, the paragraphs. You have probably (hopefully) tried out your translations on friends, family and others (ideally those that have some kind of vested interest in the thing's success); you accept the comments along the lines of "this is not easy to understand - why don't you try something along the lines of...." But suggestions that whole sections don't work, don't belong where they are, or don't belong in the book at all, are tough. I was lucky - my wife is a devoted and critical reader (and used to teach English), and I was blessed with a great editor from the publishers. I can only think of a couple of isolated instances, one or two darlings that I was determined to hold on to as a matter of principle as much as anything (the silver bullet principle), where I ended up not doing what they suggested - but the rest went and the book was profoundly improved as a result. So listen, sleep on it, and, in the cold light of day, do what these people say - you, after all, can't approach the book from the perspective of a reader. And cut. Cut the adverbs, the metaphors, the fascinating but irrelevant meanderings. I know that my wife will laugh when she reads such advice coming from me, since I have a natural tendency to meander and to construct long and convoluted sentences - but, in the end, I followed this advice (mostly).
2. Proofreading. This is a very distinct exercise from editing: it's the administration of the mechanics of the writing. Every publisher will have a particular manual of style that they want followed; for UCP it was the Chicago Manual of Style, a dry and weighty tome that is also available online (as a subscription). This is stuff that I readily admit I have little patience with, a bad attitude compounded by having divided my life between the UK and the US and having no working recollection of the differences in punctuation etc. But I had help, a taskmistress: as I wrote in the acknowledgments, "I am under instructions to say little about the role of my wife, Carol, but little is precisely what this book would have been without her. Researcher, contributor, proofreader, and interrogator of the Chicago Manual of Style, she took on all the tasks that allowed me to write the book, including, with not quite perfect consistency, having a Job-like level of patience." (There were a couple of memorable occasions on which "the f...ing book" was referred to with vigour - and justification).
Then, as the production process got underway, the publishers provided the services of a professional proofreader (a job that, to me, seems like another definition of hell). And was she ever professional and rigorous. However thoroughly you or your partner think that they have proofread the manuscript, there will always be things you missed. And, even after the professional treatment, little demons slip through: "depradation" appeared in both hardback editions until it was noted by a friend (to the immense irritation of my wife), and finally corrected for the paperback.
Then the page proofs arrive: pay as close attention to them as you can bear - they're your last chance. Because your readers are intelligent and critical folk - put yourself in their shoes and remember how a poorly edited and proofread book detracts substantially from its credibility.
3. References/further reading. Again, put yourself in the reader's shoes - how many times do you come across a topic in a book that is dealt with briefly but that you would like to explore further? This section is important (and several readers and reviewers of my book have said that they appreciate it). Of course, for a popular science book, it doesn't have to be as rigorous and comprehensive as an academic text, and there's certainly no point in including papers from academic journals that will be difficult for the reader to find. And one other note: in today's world, websites are important sources to list, but make sure that only those that are reputable and therefore likely to endure are included. The "page cannot be found" notice is frustrating for me and I worked on the principle that it would be equally frustrating for a reader.
4. The index. I automatically dislike a book with no index, or a poor index, but I know from friends who have tried to do it themselves that it's a soul-destroying task. Most publishers will provide the services of a professional indexer - but you will pay for it. It cost me $1450 (and needed improvement) and this cost came straight out of the first (and so far, only) royalty payment. After this, the subtraction of the advance, and the agent's percentage, there was enough for a not particularly gastronomic dinner out. But remember: you're not in this for the money.
5. Permissions. I was astonished to find that these were entirely my responsibility - and, along with the responsibility comes the legal liability. So I became somewhat paranoid and compulsive about this. The experience was very variable. For illustrations that I could not provide myself, it was generally the case that the copyright owners were only too pleased to provide the image for free, or, for institutions, a modest fee that would cover all future print editions (take care in all this to read the terms carefully - they often apply only to a particular edition and have to be done again for a paperback or a different publisher, and they rarely apply to electronic editions). For quotations, the experience was more difficult (and expensive). I liked to include epigraphs at the top of each chapter, and some of these, along with quotations in the text, were from illustrious writers and musicians. The pleasure of putting a few words from Jimi Hendrix against a quote from an ancient Greek philosopher, was somewhat undermined by what it cost me (Hendrix, not Heraclitus). I had toyed with great quotes from Dylan and others, but could never have afforded them. Using those eleven words from Hendrix has, so far, and after negotiation, cost me $700 - I keep reminding myself that I'm not in this for the money.
Most publishers' contracts will include a provision for some reimbursement of permissions costs, but chances are you'll still be out of pocket - avoid musicians!
Oh, and then there's the concept (at least in the US) of "fair use." Limited quotations can be used without needing to seek permission, and it's tempting to resort to this as a way of saving time (and money). But the concept is unfathomable and risky when you look at it in detail - the US Copyright Office website declares that "The distinction between fair use and infringement may be unclear and not easily defined. There is no specific number of words, lines, or notes that may safely be taken without permission." Helpful, huh?
6. The subtitle. I'll finish here with an amusement. The subtitle for a book is important - it should give the potential reader an idea of what the book's about, or at least provide a "hook." There was a long debate that used up considerable time and creative energy (but also generated much humour), around what followed the obvious, "Sand." We settled on "the never-ending story" because it suggested that it was a story, hinted at the durability of sand as a planetary materials, and reflected the symbolism of a single grain of sand that was important in Michael Ende's book (and the film) of that name. So far, so good. Until I came across the online writing of a New York Times reviewer. She expressed her irritation with a single-subject-titled book (I won't name it) on a particularly obscure and, in her opinion, uninteresting subject, and proceeded to bemoan the genre of such titles. Unfortunately, my book seems to have landed simultaneously on her desk; rather than just ignoring it, she cited it (self-respect requires me to assume that it remained unopened) as another tedious example - "Sand: the Never-Ending Story," she wrote, "I'll say!"
Oh, how I laughed. Well, at least I do now.
This interpretation had never occurred to me - or to anyone else involved. As you might have noticed, Oxford University Press changed the subtitle to "A Journey Through Science and the Imagination" - more pedestrian, but less susceptible to wit.