Placing horizontal sidebar

Hi there,

I was wondering if anyone could tell me how to place a horizontal sidebar in this layout.

.sidebar {
margin-left: -450px;
line-height: 1.5em;
position: absolute;
top: 515px;
left: 50%;
background-color: transparent;
     }

I tried using this code,but the sidebar kept overlapping with my stickypost and entries, so I modified my code to not show the sidebar for now. 

Thanks in advance.