hmm...right off the bat there's a gigantic problem i'm noticing: no doctype, and you don't even start the <html> tag. those are the two most important parts of a web page.
secondly, in the actual content area, you're using <span> tags where you should be using <div> tags. spans are usually used for single lines of text, while divs are comparable to tables.
there also will be a couple issues when you're using float, relative positioning and margins all at once.
so, it's probably exactly what you don't want to hear: i'd suggest recoding it completely.