Smilies
When typing a message there are a list of available options at the top of the message box. Eighth one along is a smilie, clicking on it show the available smilies which you can click to add to your post. Hovering over one gives you the syntax that you can type in as an alternative, often quicker.
Small Icons/Emojis
As an alternative to Smilies, there is a larger selection of smaller icons available. Just right click in the message box and select Emoji at the top of the drop down menu. There is even a search box if you are looking for something specific.
