You may use bookmarks to keep favorite websites close at hand, but you can only access these bookmarks on a particular computer. Delicious allows you to organize and access bookmarks from any computer.
If your students need to find and share websites in a course, you can create an account for that course. Dordt College’s library uses a Delicious account to share bookmarks. Arkansas Technical University’s Ozark Campus Library also uses Delicious tags.
The best idea is to try Delicious for yourself. Then you can see if it would meet some of your needs.