The Internet may be a tool that greatly expands the possibility for reference service in school libraries. However, to use the Internet, it is essential to understand the system of information retrieval and also to learn this new way of thinking about information retrieval. In addition, since the quality of information on the Internet is not necessarily guaranteed, careful evaluation of information is essential. School libraries today are using information on the Internet not only for reference service, so it is also very important to educate students about information retrieval in the process of providing information literacy instruction. In educating students about information retrieval, instructors should stress the way of thinking about information retrieval, especially the preparatory stage.