Author event?

I would list it with local book clubs and also with your local Craigslist.org -- in the General Community section. I would post this with any other local blogs that you are aware of, and definitely on the book store's site. I would look also for writers' workshops who have bulletin boards and of course, children's reading rooms and places that parents would look for information on their kids' books (libraries, etc.). Good luck -- I believe in supporting authors!!!