how to add pitcures and an article to main bodt of template

Hi all,

Hopefully this will be a quick question.

I have managed to customise the sidebat of my wordpress blog and would now like to make the part where you post comments look more attractive.

I was hoping to add an image and google adsense and an article below that. Please can anyone advise on how I need to edit the template to achieve this.

thanks very much
John