Beverly Cleary has a real gift. Although her books span a period of decades, they all read as though they were written today. There's a few odd details in some of them, but mostly they rely on good storytelling and... well, very real-seeming children.
This is the story of Ramona's kindergarten year. It can be hard to find chapter books that are worth reading to kindergarteners, but this is it - Ramona actually seems like an actual child who is actually, really, truly in kindergarten! When she's told to "sit here for the present" she does, waiting for her present. When she struggles to refrain from pulling perfect Susan's curly "boingy" hair, you can feel how hard it is. And it's easy for all small children to understand why Susan's trying to act like a grown-up is annoying for Ramona.
I would really suggest this as a first read-aloud chapter book for a young kid.