Another resource that has recently jumped onto the scene is "social bookmarking."
I looked for information about Biology, Technology, and Education on Delicious. Here are my bookmarks that I have shared. You'll also notice some political stuff, and viral videos, because that's things I am interested in, in my personal life. Each of these things I looked for would be considered a "tag." A tag is simply a term for something you a looking for. I looked for Biology, Education, and Technology. As I look at each tag, it takes me to something on the web that has been bookmarked, that has the term associated with it. The bookmarks would be pages on the web that have good information on them.