Brainy Quote - If you need a good quote to compliment your writing, Brainy Quote is definitely the place to find it. The site lists quotes by topic, author and type.
Encyclopedia.com - Writers can use the free High Beam Encyclopedia to access articles and information in the
Columbia Encyclopedia, Britannica and other reference books.
IPL - No matter what you're looking for, the Internet Public Library is a fantastic source of information.
Ref Desk - The Ref Desk bills itself as a fact checker for the Internet, and it definitely measures up to the description. The site offers numerous search engines, as well as virtual newspapers, encyclopedias, periodicals and other reference materials.
Scholarpedia - Scholarpedia looks a lot like Wikipedia, but it is much more reliable. Content is written and reviewed by scholars all over the world.
The New York Times - You can search news stories that go all the way back to 1851 with this leading news site.
The Open Directory Project - The Open Directory Project provides a directory of links. The site employs live editors, which increases your chance of finding reputable sites in each category.
Wayback Machine - The Internet Archive's Wayback Machine is perfect for student researchers that need to find information on old web pages (as far back as 1996.)