How do I add an image from my template folder to a sidebox

As with the main template, "<? echo DIR_WS_TEMPLATE; ?>" inserts the stem of the template's URL into the page.

So, if your image is uploaded within your template, then the code will be as such...

<img src="<? echo DIR_WS_TEMPLATE; ?>images/logo.png" alt="logo" width="300" height="87"/>