I'm a bit clueless and curious. What does editting a book involve?
Okay, it varies from book to book, but in general:
1) The editor acquires the book for the publisher by striking a deal with the author or agent. This involves reading submissions, negotiating the contract, and convincing the publisher to let you buy the book in the first place. ("Pretty please?")
2) The actual editing. This involves working with the author on as many drafts as necessary to whip the book into shape. I typically read the ms. through, take extensive notes, and send the author a comprehensive letter suggesting areas for revisions. ("I'm not sure why we need the villain's ex-wife. Can we cut her out of the book?") This tends to be big-picture stuff and should be distinguished from
copyediting which is more about spelling and grammar and such. (That comes later.)
3) The editor serves as the book's in-house advocate and cheerleader. You work with the marketing department, the art department, the publicity department, etcetera to promote the book. If anyone has a question about the book or the author, they come to you. ("So, Greg, what's this new Matheson book about? How many copies do you think we'll get out? Is he available for interviews?")
4) You act as a troubleshooter for whatever complications may arise, tracking down lost checks and author copies, making sure the author has a copy of the cover art in time for that convention, and so on.
That's how it's supposed to work at least. In real life, you can end up with more than one editor at various stages in the process. For example: John Ordover acquired the third Khan book and worked closely with me on the original twelve-page outline, but, after John left Pocket, Ed took over the project and did the rest of the editing. That's a not uncommon state of affairs.
And, of course, where tie-in books are concerned, you're also interfacing with the licensor, who need to see and approve everything.