These sites allow you to save links for future reference. You can even share them with friends or other web users. All of these 'social bookmarking' sites are free to use but do require you to register. You can accessed any of your saved links from any computer you happen to be using.
If you think that the info on this page can be useful for you or some one else in future then simply bookmark them by clicking on one of these links to add to your list.