There are many different kinds of sources, and they all have slightly different purposes. Newspapers are good for news coverage and providing records of events for the public. Popular magazines can be useful because they provide current information as well as easy to understand articles on a topic. Professional or trade magazines can be useful for current information about a particular topic or discipline. Scholarly and academic journals have research on a topic done by experts in the field. Books provide comprehensive information about a topic, along with background information and a bibliography. Finally, websites can provide up to date information from many points of view along with government and company information. Each of these kinds of sources has different intended audiences and things you should consider when using them.

For more information check out the UGL guide on sources.