Theme CSS… a little help?

Hi everyone 🙂

I’m setting up a wordpress based site/blog using a theme I paid for through a 3rd party. I’m now in the process of modifying it and at present I’m testing things with some preliminary ‘draft’ artwork. I’m a bit out of touch with HTML, and CSS/PHP is new to me. I’m getting my head around it slowly, and I’ve figured out how to move or change most of what I want to, but one element has got me scratching a hole in my head.

The URL is http://www.ravedigga.com. If you look you will see that from the top down there is a header image, then a gallery (featured gallery plugin), and then the body of the blog with a sidebar parralel on the right. I have added a taller header image, so then I needed to move the gallery position down the page to accomodate it. I’ve done this, but now the main body/sidebar is sitting with the gallery overlapping it. I know just want to move the top of the blog and sidebar areas down the page so they start under the gallery plugin. I’ve searched through the CSS and looked over the main index PHP, but i’m not getting anywhere.

I have contacted the theme designer already, but as yet there’s no reply (been waiting a few days), and looking at CSS tutorials online hasn’t helped. Sorry if this is in the wrong forum area (please let me me know/move the post). Please can someone guide me? I can supply the CSS if needed

Thanks
Mikey