My site www.it-pathways.com is displaying correctly in IE 9, but it looks terrible in Firefox. The header displays incorrectly and the page background is non existent.

I am not a professional developer and to be honest am not really sure what to look at in order to resolve.

I was wondering if someone would be kind enough to look over the code and let me know what I've done wrong (code structure, syntax, css or a combination?)

Thanks in advance,