Poisoned Pen mystery bookstore has a nice list of authors coming by to sign books in the next couple of months. Even if you don't live near Phx/Scottsdale, the store generally keeps some signed stock that you can order.
The events list is here:
I'm excited about the Lindsey Davis one in May--if you haven't heard her speak, she's hilarious. She will have a discussion and sign Alexandria, the newest Falco mystery. If you attend, I'll be in the audience. Laughing, I imagine.