How to add/edit/remove contacts?

When you're visiting the content of another user, in the upper part of the sidebar you'll find the "Follow updates" button . If you click on this button you will be able to add the user as a friend, an online friend, a colleague, a co-worker, etc. If you want you can skip this step. Once you have added the user, their contents will appear on your homepage.

In order to remove the user and not see their content, you have to click on the "Following" button, and in the next step you will have the option to remove the user.