When you get that email, particularly if it's your first book, make sure you are well-rested and in a positive frame of mind before you open it. If it’s your first book, the editing process will be hard on your ego, but remember, the editor’s job is to make your book better and help you learn the craft. You are paying for them to give you critical feedback, not to pat you on the back and say ‘good job.'
The single most decisive factor should be the quality of the edit itself: Will this editor help improve your book? In order to assess this, nothing beats a sample edit (even if you have to pay for it). Testimonials and credentials (such as experience at a major NY publisher) can help you narrow your list, but you should submit the same sample to a variety of editors and compare their work side by side. Some editors will push too hard, and some won’t push hard enough; some will simply “get” your writing, while others will seem to speak another language entirely. In my experience, the editor’s résumé is far less revealing than the quality of the sample edit. In fact, the higher an editor’s pedigree, the more reluctant the editor might be to provide a sample edit. Don’t be afraid to insist: no one should expect you to invest in a car without a test drive!
Stephen, you’re right, and I think much of the confusion about editing and its pricing stems from the fact that editors offer a range of services (in addition to a range of experience). It might be best to view editing on a spectrum from broad (developmental) to detailed (copyediting and proofreading). And it’s always best to have as clear an idea as you can about the kind of editing you believe you need.
Excellent advice, Teymour. I’ll add this food for thought if I may… ANYONE CAN WRITE. Few people write well. Even fewer can tell a good story. IF YOU CAN TELL A GOOD STORY, and you’ve been working on a book but your writing skills are a little rusty, you need an editor who actually cares about your success, who cares about making your book the very best it’s capable of being. That usually takes an editor who instinctively goes above and beyond what’s expected. Every single author, every single story is unique. Each deserves the undivided attention of the editor.… Read more »
I cannot speak for all editors, of course, but I know I and many of us would be open to editing just part of your book at first, say, a particular chapter or two that you sense needs a lot of work. That is often enough to show you mechanical errors that you tend to make repeatedly. You can then go through the entire manuscript yourself looking for as many of the same kind of errors as possible. You will sharpen your basic writing skills in the process, and it will pay off in all future projects.