[thelist] basic Joomla question

[Nan Harbison]

Hi Evolters,
 
I have been asked to add a graphic for a sponsor of an event to a website
created with Joomla (they asked if I knew Joomla, I said sure! Does anyone
else do that, ha ha, I know I will figure it out.) I know Drupal better, in
Drupal terms, I am looking to add a block to the left side of the page under
the main menu. I have uploaded an image to use, which has to be a link. 
Can someone point me to the Joomla term for what I am trying to do, is it a
component, or section or category? Is this a banner? And how do you add this
to a page?
 
Thanks!
Nan