"Classic" Little Golden Books

All of the Little Golden Books from the 40s-70s are definitely what you're looking for, and you can often find them in thrift stores and used bookshops. Some are still getting new editions printed by Penguin RandomHouse.

I also love Sally Hunter's Humphrey books, they're all about a little elephant named Humphrey and the illustrations are so rich and atmospheric. I have two prints framed in my bedroom!

Anything by Beatrix Potter, too! She's most famous for The Tale of Peter Rabbit but she has over 20 children's books. She was also a natural scientist and you can really feel just how much she loved studying nature in her drawings. (She was also a very early female entrepreneur and Peter Rabbit was the FIRST licensed character ever which I think is pretty cool.)