After you sign the contract, your agent and the publisher's acquisitions editor will walk you through their publishing process and timeline for your book. You'll likely be assigned an editor who will be your point person throughout the entire editing process, which may include rounds of developmental (or content) edits, line edits, copy edits, and proofreading.
Your editor will be your main contact at the publisher, but they will not be the only person you'll work with within the house. You'll have an entire team focused on preparing your book for publication, including multiple editors, a cover designer, a publicist, and possibly more. Smaller houses may have team members perform multiple roles.
The publishing process may feel like lengthy, but many activities are taking place. The first set of activities are focused on editing the manuscript, which can take multiple rounds and months of going back and forth with editors.
During the editing process, other activities kick off. A cover designer will create the book cover based on input from the editor and writer. Note that the writer rarely has final approval of the cover—the publisher does because they want the cover to mesh into their overall catalog and demographic.
The book's publicist develops a publicity plan for the book release. The amount of marketing and promotion provided by a publisher varies by the book and writer. An author with a history of bestsellers will receive a far greater promotional budget than a debut author. All writers are expected to promote their own book besides the support a publisher provides, so I'm hoping to add a Part Four to this guide at some point to cover ideas for you on review copies, ads, newsletters, social media, and more.
One promotional item created for most books is the Advance Reader Copy (ARC), which is an early copy (sometimes not yet proofed) that the writer and publisher can provide to reviewers and other sources for early word-of-mouth promotion.
As the release date approaches, the book files will be formatted, the book description will be finalized, and your author biography will be needed. All the hard work culminates in a professionally released book that makes you (hopefully) proud.