Kdude,
Different publishers will do different things. Some will arrange signings for you, others will leave it up to the author. In my case, I arrange signings myself--I think it's just a lot easier, what with working a full-time job and having other commitments. The bookstores are very familiar with my publisher's books and they are all happy to have me come in usually on days of my own choosing. After I schedule them, I email the publisher to let them know of the events. The publisher then sends announcment signs and makes doubly sure the stores have plenty of stock.
Bookstore managers will also arrange signings, perhaps for a local author day or some other event. When this happens, they will usually contact the publisher who will then contact the author. You don't have to participate if you don't wish. But as stated in a previous post, multi-author signings are fun.
I never expect to sell a ton of books at a signing. I think the most I sold of one title was 15. My average is seven. Since I came out with book two last year, at my signings I sell an average of seven of one and six of the other. This year, I will have three different books on my table, so we'll see what the new averages are.
Even though my books are regional history titles, the subjects appeal to a lot of different people including tourists and railroad enthusiasts. The new title is entertainment history which will attract a new audience.
And yes I have had signings where nobody showed up. This was inside a mall where outside it was an absolutely gorgeous perfect fall day. Nobody was shopping. But that was OK; I just sat there and read. (Normally I stand in front of my table.)
I love doing signings. I love to meet people who have either read my previous books or watch people flipping through it the first time. I always hear the same stories about the subway or streetcars they used to ride, but that's fine with me. It gives me a common ground with the customer.
I also love speaking to groups. I have spoken to just a few people to groups of fifty or more. As long as I know my subject, I am perfectly comfortable giving a talk. Talks raise awareness about my subjects and teaches the audience some local history.
I don't believe publishers actually require book signings and public readings. In fact, many authors are reclusive and don't ever give signings. But authors are expected to participate in promotion--especially at a local level, while the publisher does all the really hard work. Certainly you don't have to, but what does it hurt? Readers love to meet the authors of their favorite books.
And if nothing else, it is a lot of fun to go to your favorite bookstore to sign their stock and soak up the praise from bookstore staff on why your books are so great and how they sell so well.
Maybe that's not what writing is all about, but it is a nice perk.
Allen