Publishers are very busy and the in-house PR folks typically work on 18 books per season which doesn't leave them much time for any one book. To insure that this doesn't happen, it's advisable to have your own publicist working hard on your behalf. In the best of all worlds, four months before the publication date. This way they can begin pitching the monthly magazines which have at least a 3 month lead time. Many of clients are signed up with us six months prior to publication and we begin working fours month prior.
Most cities have morning local TV and radio shows as well as daily newspapers and local magazines.
You may also have radio phone interviews to do during the day for stations across the country. Your booksigning will usually be at 7pm. Often times the booksigning will have a small turnout but by doing the signing you get great placement in the store which will increase your sales. Most bookstores will include you in their mailer that goes out to their database and do in store flyers. All of this will help promote your book.