First Day Jitters, by Julie Danneberg (I use this one if I have kids who are very nervous)
Miss Nelson is Missing, by Harry Allard (A good book to teach about why it's important to have good behavior)
Countdown to Kindergarten, by Alison McGhee (Set the tone: Kindergarten is Fun!)
How do Dinosaurs go to School?, by Jane Yolen
How do Dinosaurs Learn to Read?, by Jane Yolen
I Like Me!, created by Bell Atlantic Pioneers Paumanok Chapter. (Make "I Like Me!" signs after reading this book!)
May I Bring a Friend?, by Beatrice Schenk De Regniers