Writing a book is not as tough as it is to haul thirty-five people around the country and sweat like a horse five nights a week.
- Bette Midler
Writing is tough - even writing funny books, skinny books, picture books, thick books, serious books, kids books. 
Yet lots and lots of people say that when they have time they'll write a book. They usually aren't so crass as to add that they know their book will be published easily, it'll become an overnight success and they'll be not only admired, but also become rich and famous.
A reality check is needed here.
Do you want to know the truth about authors?
They write because they are driven to write. (Latest research has identified this disorder is linked to a recessive writing gene that appears in selected crazed ancestors from time to time.)
What does being a kid's author really mean?
Writing, editing, being excited, insecure, neurotic, thrilled ... about your new creation. The book.
Then there is the agony of waiting, waiting, waiting. Publishers take forever to look at the book. If you're a new author, waiting a year to get a response is nothing, that is if they even look at it. Then it's usually rejected. If you're a published author it is quicker, easier, but it doesn't mean it'll be accepted for publication.
Once accepted for publication, the whole process starts. Drama about contracts, editing, covers, publications dates, distributions, discount sales...
After it's finally released, there isn't much money for most authors and you start the whole writing process again.
So why be a kids' author?
Because you like to make kids laugh or think or open the world of reading to them. You'd like that transition from childhood to adulthood to be less confusing. Maybe your books will help them on their way. You want kids to experience your books.
The "love" letters authors get from kids are precious. When they write and say in their best kid's handwriting "I have now read the book 2 1/2 times and am nearly finished for the 3rd time", it makes being a kid's author fantastic.
Why visit schools? 
It's hard for authors to visit a school, find their way around, confront large groups, deal with undisclosed curriculum issues. Authors aren't trained to be speakers and performers. Many authors are nervous and unsure when they do school visits, but they still do them. Why?
So here are some guidelines: -
What to do when a kid's author visits your school.
At the end of an Author Visit, there should be a feeling of goodwill between the Author, Teachers/librarians, students where they have been brought together through writing.