How to add a banner image to the top of the /blog page

I'm trying to add a banner image to the top of my blog page in Catch Everest Pro. I've already managed to add the following code to the single.php file and it's working on individual post pages. <a href="http://www.yumtumdelivers.com/blog"><img src="http://www.yumtumdelivers.com/wp-content/uploads/2013/01/the-baby-food-aisle.jpg" alt="The Baby Food Aisle" /></a> Now i just need help getting it on the main blog page itself. I got it partially working by adding the above code to the content.php file, but the banner appeared multiple times on the blog page, in between each post...can anyone tell me what I'm missing? Does my code need tweaking? Thanks for the great theme.