A subject directory is an Internet resource that organizes Internet resources by subjects or topics. Instead of a computer program or application, an actual person makes the decision about what information is included and how it will be organized. This means that while the information listed under a particular topic may not be as extensive as the results generated by a search engine, they tend to be more focused and to the point.
Subject directories are great places to start your research and can be very useful to students in researching or narrowing a broad topic. Most directories can be searched by keyword or browsed by topic. Some offer advanced search options, while many have become portals, offering special features like information guides, free email, multimedia resources or current news.
Open Directory Project
Librarian's Index to the Internet