The book The Mitten is by Jan Brett. She has lots of wonderful children’s books out, and she is best known for her intricate illustrations. If they like The Mitten, try The Hat. She has a website, too. Her books have been around for a long time, so they should be very easy to find. I’ve been working on my knitting and purling tonight–very uneven. Oh well. Kindergartners are very forgiving. 
The Mitten
Thanks so much Kelley. 
I just put those 2 books on hold at our library.
Took me a while to clue in to what book you were talking about, but now I remember. Wow! That’s going on my booklist for my son. He’ll love it!