Add a hyperlink to image in sidebar?

Hi All:

I’m sure this is pretty easy to do, which makes it all the more painful to ask. I’m trying to add a hyperlink to the sidebar in a site I’ve inherited management of. In the past I worked with HTML but I’m new to PHP. Basically, I want to make the organization’s logo on the sidebar link back to the homepage. When I go to the sidebar.php in the theme folder I am redirected to the function.php folder. Once there, I can’t seem to find the image.

Any help would be appreciated.

Josh