Use web directories when you would like to browse the internet in a subject area. Directories list web sites that are compiled by experts in a particular field.
Search Engines are useful when you know a particular group or site for which you are looking. For example, if you are looking for the Official Vatican website, a search engine would be the best path. They are also useful for more ambiguous searches since they are able to combine search terms.
The Invisible Web
Use the "Invisible Web" to find information stored in databases. Databases you may find include directories and lists of facts and statistics arranged by subject.
Research Paper Help/Citation Guide
Citing sources from the internet can be challenging. The following links lead to examples of different citation styles.