While most reference sources are thought of as being either print or online, there are a number of other library resources that take other forms. Video, audio and image collections are also useful when answering questions or supplying students with information. While not all of the following links are necessarily 'reference' sources, it's important to consider them when thinking about your library.
Traditional videos may still be a big part of your library collection. When purchasing new materials, think about the format (VHS, DVD, BluRay, streaming) and how these technologies are supported in your school. Also remember that performance rights are required if you will be showing a video for non-educational purposes (either in- or outside of the classroom).
Depending on your school, some of the following sources may be blocked.
As with movies and films, audio material can be a big part of your library. While the free online options are somewhat limited, there are ways to search Google for audio materials. Just remember that downloading any audio without the proper permission may be illegal.
Google has a powerful search interface for images, but many of these files are copyrighted and not freely available for your use without the proper attribution. Other sites, though, such as some listed below, offer free images with varying degrees of usage permissions.