For the smilies:
You should be able to click on one of them on the left. Using [get more] will bring up another window with more choices. When you click on any smilie, it gets placed in the message (although the popup window doesn't close).
:scatter:
You can also type them in manually if you know the name that's associated with the smilie that you want to use. For example, the one that I placed in my message is called scatter. If you put that word between 2 colons ( : ) then you get the same result as clicking on the image from the menu.
Hope that helped.