I'm going to let this stand alone for a bit, then I'll merge it into another thread that's stickied with answers to lots of "how-to's".
For now, I'll leave it like this as there are several having difficulties finding out how to edit, select, change their moods...understandably so as it's potentially hidden for some to most.
To be able to view your mood settings, you cannot have *any* notifications (private messages or new friend/group requests). Those *all* must be cleared, marked as read, etc.
To find your notifications, look just under your private messages statistics on the upper left-hand side of the main forums index page. From there, click on the little drop-down arrow to the right of the words. It will show you all notifications you have. Clear them by accepting, not accepting, marking read, etc.
Once all notifications are cleared, the mood icon will automatically show itself, as will the capability to change it.
You can see where my mood settings are located in this screenshot (again, on the main forums index page). If yours isn't showing, please go through the above steps. If that doesn't work, please contact an admin via PM and we'll find out what's going on with possible further instruction (clearing cookies, cache, "hard" refresh, etc.).
Good luck!
KD