1. At this age children are developing their language skills rapidly, learning new words and meanings everyday, introduce shapes, numbers, colors, and animals now.
2. These children are just beginning to understand right and wrong, so books with morals and themes are good subjects.
3. At this age children are trying to figure out their environment, they want to be reassured, not frightened.
4. Kids under 6 have short attention spans, you'll need short, catchy sentences, rhymes or patterns. Make sure the book can be read in one sitting.
5. Children this age like to participate; songs, repetitions and read alongs are great.
Now, take a look through a few of your favorite PB's. Are these same developmental levels present in the writings?
Inspiration taken from- You Can Write Children's Books Workbook, by Tracey E. Dils.