How would I go about inserting a small banner or link in this area? I know it's the header, but what code would I use?
Use the <div align="right"> and </div> tags in combination with <img src="path/to/image/" /> or <a href="/path/to/link/">text here</a>
No matter how I try and insert the code, it'll show to the right, but it's either above or below the logo, and not on the same level!?
Before the code for the logo image (on the left), insert:
<div style="float: right"><!-- code for whatever --></div>