Natasha Wing has a wonderful one titled The Night Before Preschool. Young Billy is nervous about starting preschool and cannot sleep. The reader is taken through a typical day at preschool with Billy - circle games, snacks, projects, reading, etc. When it is time for nap, Billy is so upset (he forgot his favorite stuffed animal) that he cannot fall asleep. A little girl hands him one of her plush pets, winning Billy sleep and a new friend. Ivy is left with the knowledge that preschool will get better!
The Kissing Hand by Audrey Penn is another fabulous one. Ivy has me practice kissing her hand and making the kiss go straight to her heart so she knows she is loved all day like little raccoon.
An absolute Ivy favorite is Llama Llama Misses Mama by Anna Dewdney. Little llama is heartbroken when his mama drops him off at preschool. He cannot even be distracted by trains, stories, or snacks. When he breaks down in tears, his classmates help to stop his sobs and help to make him enjoy preschool. At the end of the day, little llama realizes he loves his mama and school too!
I Love You All Day Long by Francesca Rusackas and Pricilla Burris
D.W.'s Guide to Preschool by Marc Brown
Maisy Goes to Preschool by Lucy Cousins