Okay kiddo, have you ever borrowed a book from the library? A bibliography is like a big list of books and articles about a specific topic that someone has written about or studied.
Now, imagine there is a big group out there, called Scientology, and some people think that the group is not very nice or helpful. They have written books that are critical, or disagreeing, with Scientology and the things it says and does.
The bibliography of books critical of Scientology is a list of all those books that people have written on this topic. So, if you are interested in learning more about what these people are saying, you can look at this list and choose which book you want to read.