I'm not sure what you mean by "find". Here is list of child books http://book.naver.com/category/index.nhn?cate_code=320&list_type=&tab=recommend Most books are paper books, but some books are e-book which can be bought and downloaded online.

There's a cellphone app called BeeLingua that you can use to download books of various levels in a variety of languages. You can see both languages at once and hear it read aloud.