Okay kiddo, so a bibliography is like the list of books your teacher gives you to read over the summer. It's all the books that someone has written or talked about related to a specific person or topic.
Kim Il Sung was a very important person in North Korea. He was their leader for many years, kind of like the president. A lot of people wrote about him and his life, so a "Kim Il Sung bibliography" is a big list of all the books, articles, and other things that have been written about him.
It's important to have a bibliography so people can find useful information about someone without having to look through everything ever written about them. Does that make sense?