HTML and CSS Homework

Anybody good with design? I have a project where I have to make images into a drop down menu. I have the CSS/HTML for the original design which needs to be converted into a nicer design using the same images, but making them into a drop down. Here is the link of what it looks like at the moment:

 

http://www.telepresenceoptions.com/sponsors/

 

Need to make the images into drop down so that all of the links do not show and take up space.