One of the biggest frustrations I hear from editors and book layout people is that authors don't understand what proofreading means.
As a simple definition, proofreading is reading an already finished and polished manuscript to look for any last errors that might have been missed when editing. If a manuscript is ready for proofreading, then the errors found should be fairly minor and probably not more than one per page, hopefully far less. Proofreading does not include editing or rewriting.
Many an editor has had an author approach him with a manuscript that is said to need proofreading but really needs editing. Editing is far more substantial than proofreading-it can involve rewriting sentences, deleting unnecessary content, writing in new content, moving around sentences, paragraphs, and even chapters, and also fixing grammatical and punctuation errors. Many editors will differentiate between copyediting, developmental editing, or other types of editing. A good editor hopefully will do all of them for you, but remember that not all editors are the same. You might find a great editor who can do a developmental edit to improve your book's content, to develop your characters or help to strengthen your plot, but he might not be so great at knowing comma rules, how to catch split infinitives, or at fixing subject-pronoun agreement issues.
Every book needs editing. If an author says a book needs proofreading, it most likely needs editing unless the author has already had someone else edit the book, and even then, only if that person is qualified as an editor.
Most editors will do a free sample edit of a few pages of a manuscript so the author can see what needs to be done in terms of editing-sentence structure, organization, grammar, and punctuation-and after the sample edit is done, the author will generally agree it is editing, not simply proofreading that needs to be done, if the editor knows what he's doing. It doesn't hurt to get a few editing samples before choosing an editor to make sure you find an editor who will give the book the full attention to detail that it needs.
After the editor finishes editing the manuscript and the author is happy with the edits, it's important to find a third party who is really good at proofreading to go through the manuscript to catch those few errors the author and editor did not catch; your editor might proofread for you, but a third set of eyes is never a bad idea. Just make sure the person is a qualified proofread-your wife or best friend are most likely not.
Once the proofreading is finished, the manuscript is done and ready for layout. Here is where "proofreading" again becomes a term that authors fail to understand and that can frustrate both the editor/proofreader and the layout person.
It's been said many times that no book is ever finished. We simply choose at some point to abandon it-which often means we believe it is ready for publication. No book that has ever been written has been perfect, and no book has ever suited everyone's tastes. You might produce a beautifully written, grammatically correct, perfectly punctuated book, but it could still have some rewriting done to make it better. The problem is, once the book is sent to the layout person, the author must restrain himself from rewriting. An author should be absolutely confident that the book is ready for publication when it is sent to the layout person. If it's not, then keep editing and proofreading. Just don't do it after the book is laid out.
Layout people do not read the books they lay out; they are not editors or proofreaders, and they will not fix your typos and other errors unless you find them and ask for them to be fixed.
The layout process includes converting the manuscript into a new program. Today, authors generally write books in Microsoft Word or some other word processing program, and editors will edit the book in the same program. But when the book goes to the layout person, the text is converted into a design file, such as InDesign, a program made specifically to design a book.
The layout person will send the proofs-the completed laid out book in pdf format (or occasionally paper)-to the author to approve. At this point, only proofreading should be done. The pdf is not the book but a copy of the book, and it cannot be edited directly. I know many editors and layout people who have been extremely frustrated with authors who decide at this point that they need to insert sentences and paragraphs, reword phrases, and flip around chapters. Once the author receives the proofs, whether as a pdf or in paper form, the author should only look for typos, and every change should be deemed absolutely necessary. Only the layout person, not the editor, can make any changes the author wants, although any changes should be run by the editor to make sure grammatical errors, of which the author might be unaware, will not be introduced into the text.
It can be very time-consuming for everyone involved if the author decides to make changes to the proofs beyond fixing a few typos; a paper printout of the laid out book must be marked up, or a separate document created in which are written down all the requested changes with page number and page placement for easy reference. The more corrections requested and more extensive they are, the more likelihood that further errors will be introduced into the book. Stylistic preferences do not count as corrections and should not be made at this point-only the correction of serious errors. In short, after the book is laid out is not the time to rewrite.
Many layout people, and especially the print-on-demand subsidy publishing houses, will charge authors for any changes they make to the book because so many authors have failed to understand that once a book is laid out, rewriting is not appropriate. Other layout people will allow a set number, such as twenty-five or fifty, corrections for free, and anything over that will be charged by the hour or by the individual correction. Some layout people will even request the author make the changes in the Word document if major rewriting is needed, and then the book will need to be laid out again, and the author will be charged accordingly since it may well be less time-consuming for the layout person to lay out the entire book again than individually have to insert a couple of hundred small changes-and again, don't forget that each correction made has the potential for introducing a new typo.
Authors, make your life easier and your layout person and editor's lives easier. Learn the difference between proofreading and editing and when one or the other is needed. When you sign off on that manuscript as finished and send it to the layout person, make sure it is as perfect as it's going to be to save everyone time, money, and frustration. Then the last stage of the book's production will go easily and the book can quickly be sent to the printer.