Two stage mouse over button question

Temporary post here. Can anyone out there help me with my CSS and HTML? I would like to give a little action to my buttons at the bottom of my sites like the example below (please mouse over the graphic). I can not for the life of me figure out how to code it so it does what I need. Can anyone help? Below the graphic is the code snippet within my template for the newer/older/home page graphic links. Thanks in advance!