Editorial process begins for fiction author who has already written book. Author delivers on time. Publisher line edits. Queries are sent to author. Editor reviews and, if corrections, input onto disk.
Publisher decides, based on advance sales, advance paid, etc. how many to print.
Sometimes, publicity sends out galleys or bound galleys to reviewers. Sometimes puts great quotes on book jacket. Book arrives in bookstores. 6 week window of opportunity. Perhaps author does mail order.