Do you have a burning desire to write a picture book for kids? Or maybe a book of verse or poetry? Many would-be authors who want to know how to write a children's book have the mistaken idea that it's a lot easier than writing for adults.
It's not really. Yes, it's shorter, but you still need the same structure to your kids' book as you would with a book targeted to adults.
But how do you go about it? You need to find your inner 6-year-old (or whatever age you are targeting) and remember and understand exactly what it is like to be a child. If not, you will not be able to "speak" to your young readers, not in any kind of authentic way. And believe me, kids know when you are not being real.
One of the best ways to achieve this is to observe children. See how they react to certain situations, and compare this with what you think your own reaction would be. How does it differ? Kids just don't look at things the same we as adults do. Everything is a lot simpler for them.
Try to look at things in a new way as you would as a child. Remember back when you were little and you first learned to ride a bike or first learned to tie your shoes. Do you recall how wonderful that feeling was? You need to be able to reach into yourself and bring these feelings out when writing your children's books.
Most importantly, it is imperative that you as an author of books for kids, take the attitudes of children seriously, i.e. their joy, their sadness, their happiness. Let this come out in your writing, and your books for children will be authentic and real and well loved.
You will not believe how quick and painless it can be to get that novel finished and ready to go to the publisher.