In your experience (and from the people you know), how much work goes into into a manuscript after you’ve signed with an agent and before the work is ready to submit to publishers? And what is that process like?
This varies very much from book to book, and agent to agent.
With Give Up the Ghost, my agent at the time asked me to do some line edits and expand/add to a few scenes. She wrote comments and corrections in the manuscript using Track Changes, sent that to me, and I revised based on her thoughts. Timeline: I signed with her in late October and the manuscript was ready for submission in early December.
With The Way We Fall, my agent didn’t ask for any changes. He felt any concerns he had were minor enough to be considered personal taste, and it would be better to leave that to the editors. I volunteered to make one small change based on comments I’d gotten from a couple other agents I’d talked to, which took maybe half an hour. Timeline: I signed with him on a Friday and the book went on sub the following Monday.
Obviously, how things worked with TWWF is about as fast as they can go. On the longer side of things, I know authors who’ve spent more than a year revising for an agent they hadn’t even signed with yet before that agent offered representation and went on to submit the book, and who continue to work for several months on new projects with their agent.
Some agents are very editorial and want a real hand in shaping a manuscript. Others will only get involved if they see major problems. Some are not editorial at all and expect their clients to send them work that’s already submission-ready. Just one consideration to keep in mind if you’re looking for an agent yourself, and trying to figure out who would be the best fit!