Del.icio.us is fantastic! It has become one of my favourite internet tools since I learned about it last year. What it does is allow you to save links to webpages that you can access from any internet connection, which is a whole lot better than just having a Bookmarks or Favorites folder on your computer (because you can only access those bookmarks from that computer). All you have to do is create a free account and start posting (adding) websites.
Take a look at what the PRHS library account looks like.
When you post websites you can also add tags, or descriptive words to help you find that website later in your del.icio.us account. For example, if you added this blog to your del.icio.us account, you might use the tags "PRHS," "library," and "blog." I currently have 90 items in the PRHS library del.icio.us account and my tag cloud looks like this:
The bigger the tag in the tag cloud above, the more posts I have tagged with it. Also, if you click on one of those tags, perhaps "astronomy," you will get a list of all the websites that I have tagged with the word "astronomy." You can also bundle the tags, which basically makes folders that contain all the posts that contain a particular tag or set of tags. If you go to http://del.icio.us/prhslib/space it is the bundle of all the posts that contain the tag "space."
You might have noticed that anyone can look at the PRHS library's Del.icio.us account and its contents. Although I am the only one who can add more websites, anyone can access the links themselves, which is great for student projects (like the grade 9 project on space) because it is accessible from any internet connection.
So, if you are interested in making your own del.icio.us account, go here to get started.