Please understand that this phrase also includes illustrators. Children get excited when an author comes to visit them. They want to read more and write more. They discover that they don't have to necessarily work a nine to five job when they grow up.
Ordinary people can grow up and do what they love to do and even get paid to do it.
Northern California is one of the best places to look. Use this website to find someone who lives near you. You can expect your author to be professional and to give your students a stimulating, exciting visit. The author should present you with a choice of programs, of varying lengths and content. Ask if their programs can be adapted to fit the needs of your curriculum.