Honors Option Nav CSS

I can't decide whether I want to to vertical or horizontal navigation for my honors option site. The challenge is to only use one graphic, the header (which will have a transparent or white background... which would load faster, Joy?) for the navigation. I'm planning on using lots of CSS. :)

Whether I choose horizontal or vertical navigation, I want to use classes like this:

a.red:link {color: #009900;}
a.red:visited {color: #999999;}
a.red:hover {color: #333333;}
a.red:focus {color: #333333;}
a.red:active {color: #009900;}

And the code for the first nav option would look like this:

<a class="red" href="bio.html">Bio</a>

Now I need to learn how to make all of the boxes the same with. I know Entropy4Atrophy had a post about horizontal and vertical navigation. Now I just have to read it (again) and understand it.