ok first of all i see that you are using the default wordpress theme and you have chnaged it a bit, well you have some errors, for example teh site does not open correct for me under safari
here is a link to the css validation page
http://jigsaw.w3.org/css-validator/validator?uri=http%3A%2F%2Fwww.yourbackyardherbgrowers.com%2Fblog%2F&profile=css21&usermedium=all&warning=1&lang=en
and your xhtml validation is a horror
http://validator.w3.org/check?uri=http%3A%2F%2Fwww.yourbackyardherbgrowers.com%2Fblog%2F&charset=%28detect+automatically%29&doctype=Inline&group=0
over 100 errors
now to your question this can be done by adding a div before the post loop, and styling this div in your style.css
or put this div after your header