In my experience as an author, the best book signings to schedule are through bookstores. The reason is they will supply the books and take the sales and this will save you a lot of money, time, and the responsibility of handling payment.
The other choices are libraries and literary events. If a library schedules an event where there is more than one author attending, it can be worth your while. However, you will have to supply your own copies to sell and take money from patrons. It is often difficult for many an author to sell a lot of copies at a library when solo. You sit there by your lonesome hoping patrons will buy a book. The thing to remember is people go to the library to check books out for free. I have had three library signings in the past and honestly they were not successful.
Some literary events such as book festivals can be very expensive. For example one book festival near me charges authors between $75 and $100 per table, and an additional fee to rent a canopy for $150. A canopy is required at this particular event. I've learned to watch for the events that do not charge, that supply a table and chair, advertise, and host multiple authors. I'm attending one this Saturday. I'll let you know how it goes.
Some bookstore chains require your publisher to contact them to set up signings. My suggestion is to make a list of bookstores in your area within a mileage radius you are willing to drive. When your book is about to be launched, ask the publicist at your publishing house to call and schedule signings. Though it would be nice to walk into a Borders or a Lifeway Bookstore, meet the manager and set up a signing, having the publicist handle it has a more professional touch. That is not to say you shouldn't stop into a store and introduce yourself. Give them a handful of bookmarks.
So the bottom line is to be selective, choose venues that will supply books and handle payments, and team up with other authors. But if you do attend an event where you have to supply your own books, check with your publisher about your discount. Don't solely rely on getting the best discount from them though. Do an online search of bookstores and check prices. I was stunned when I found a bookstore willing to sell me copies at 70% off the cover price.
One more tip: You can advertise your signing on Book Tour. Members are sent updates through email of authors signing within driving distance of their zip codes.http://booktour.com
For those of you who have had book signings, what are some of your experiences?