Wikipedia, too. Whenever I first begin a project I almost always go and overview it through Wikipedia. It’s a great introduction to a subject, also connecting you easily to other related ideas, people and places.
But it’s not all you have. Now, put aside the enormous amount of electronic resources your school gives you access to that you never use, this is mostly resources anyone can use (with a couple of notable exceptions). Some even make use of Wikipedia, though not in the usual way. We’ll start with general resources, and then get down to the resources available to a few specific disciplines.
Bartleby - This site has far more than quotes, you can find full texts here as well - poetry in particular.Citizendium - This is supposed to be the more “professional” Wikipedia. So far it’s not really taken off, but the information here is often a bit more “elite” but usually not as detailed.Answers.com - Answers.com is a sort of “commercial” Wikipedia. It makes use of the info on Wikipedia, combined with many other reference sties, to become a one stop shop. It also has a mobile site that I tend to use a great deal.ePodunk - If you’re looking for information regarding a city or place, it doesn’t get much better than ePodunk.
Encylopedia Britannica - I know it seems awfully “old school” but this site is an excellent source of information and much more authoritative than Wikipedia.
Scholarpedia - A step up from both Wikipedia and Citizendium in terms of scholarly respectability, it doesn’t have nearly as much information, but the articles have all been written by experts with peer review. An academic paradise!
JSTOR - You know all those stuffy journals around your professors office? And those articles in your course packets? This is pretty much that. For research it enormously useful.
Oxford English Dictionary - The definitive resource when it comes to the English language. Not just for English majors, the OED (as it’s known) is useful for almost anyone in the social sciences.
Wikiseek - When you absolutely, positively, must have the real thing - WikiSeek is Wikipedia with a better search engine. I would also suggest WikiMindMap for when you’re trying to get a better holistic grasp of a subject.