As it’s about page says, del.icio.us is a collection of bookmarks, yours and the collectivity ones. You use it to pin your favourite sites and organize them not in folders anymore but by tags. By saving your links on a remote server, you don’t have to import/export/backup them, they are always there, even from another computer.
It is extremely useful if you want to:

  • Organize all your bookmarks in a useful way
  • Have a link under the attention of a friend or coworker
  • Discover new links by looking at what other people are bookmarking
  • Assign a link the collective tags, so you don’t have to write them yourself
  • Have a network of friends, whose links are more relevant for your activies.
  • Add a person’s feed to your RSS reader

How to access to all this information goodness? You start from the del.icio.us homepage, create a free account by clicking on "get started". Fill the form and you are ready to go.
Now, you can add your links from the del.icio.us website, or by using a third party tool. The service itself promotes an extension for Firefox, but I suggest to use the one provided by Yahoo! Inc. because it is more feature complete.
Upon installation, the extension starts to import all your existing bookmarks into your del.icio.us account, automatically tagging them. Let it be and wait for a pair of minutes. Next operation in line is to hide your existing bookmarks interface to use only the del.icio.us one. On the upper part of the Firefox windows you’ll notice, amongst others, a del.icio.us menu. From there, the last voice is ‘Hide bookmarks menu’. Now you can add a bookmark clicking the ‘tag’ icon or by pressing CTRL+D, browse bookmarks clicking the ’search your bookmarks’ icon or by pressing CTRL+B, or do the same actions from the menu.
When you add a bookmark, a new window will appear, with Recommended, Network and Popular tags.
Clicking on these words will tag the link, the recommended tags are from your existing link library, while I sometimes find the popular ones to be more fitting. If you are unsure, better more than less, you can refine these later. If nobody has the link in his del.icio.us (this means you’re the first to discover this resource, in the network) you have to manually add the tags. Remember, tags are separated by spaces, so you can’t write for example ‘web 2.0′, but ‘web2.0′, not ‘New York’ but ‘NewYork’.
To exchange links with your friends (they should have a del.icio.us account too) simply click on the Network tags of your friends. When you’re ready, you press ‘Save’ and the bookmark will be saved.
Adding a friend is done by going on your friend del.icio.us site, then clicking on the link ‘add … to your network’. Many blogs (like this) have ready made links to add an article to del.icio.us (if you don’t have the extension installed) and even add a person to your network (like my Add me to your network link).
To check the links inbox, from the del.icio.us menu, choose del.icio.us website, then Links for you. Be sure to have a look to Popular and Recent bookmarks, there are very interesting things there. Nearly all the pages can be formatted as RSS feeds to use in your favourite aggregator.