just click on add to buddy list in the person's profile or click on the nick of the person in a thread and go to add personx to your buddy list~
You can check on your buddy list after by going in your user control panel
Whoever is on your buddy list will appear with a + besides their nick afterwards (its actually after their nick)
But yeah since the + isalmost?the same color as everything else, its not really that easy to see if your buddies are on in the list~