Delicious is a free social bookmarking site, affiliated with Yahoo. It's sort of like a favorites folder in your internet browser, but it is stored online. That means that you can access it from anywhere. You can also share your bookmarks with people. When you bookmark a site, you should enter a couple key words to tag it. As your sites grow in number, they will organize themselves according to your tags.
If you have a Yahoo account, you can use that to sign in and create a Delicious account. This Web 2.0 technology is easy to use. In less than three minutes, I had already created an account and bookmarked a couple sites. All you have to do is click on "save a new bookmark." Then copy and paste the address from the website into the box. Click "Next." Most of the time, Delicious will fill in the title for you. But you can change it to make it useful to you or your students. There is a box for you to enter notes/description of what the web page contains. "Tags" is where you enter the key words. The "For" box allows you to choose which email addresses or Delicious users to send this to.