My 2 year old son loves this book! We started reading a few weeks before preschool began, and it really helped him know what to expect at school. Even after school started, he wants to read it every night and tell us what he does at school that is just like Corduroy, as well as what is different. We've been able to discuss sharing, his teachers, and get more information from him about how he's feeling at school.
The illustrations are vivid and colorful, and there are no errors in the book as the one review stated. The writing is nothing spectacular, but its really more about the story teller's skills when kids are at this age.
One word of caution: the pages are soft, as are the flaps, not like board-based lift-the-flap books. If your child is very rough with things, this could tear pretty easily.