If you’re interested in what the author has to do with a manuscript between writing “The End” and seeing it in a store, check this out. Established author Lauren Willig gives an overview with the timeline from one of her own books in this blog post.
I asked for details on how this might differ for a first book, so check the comments in case she writes more!
Oh, if you’re wondering why I didn’t put the actual blog post here, it’s in case she gives more good info in the comments – I wouldn’t want you to miss them!