No offence, but please don't listen to this. Anyone can code a site and run it through the validator and have it valid. All that means is you've closed all the tags (and some more such as what can be inside what elements) but does not mean the site is WELL coded or semantic.

Can't argue that. I can code a site with SO many wrong ways of doing things, and still get it through the validator. On the flipside, I can also have a perfect XHTML Strict job, add target="_blank", and it's not valid. Does that mean the really bad job is better than the good one, just because it's valid? Of course not

@OP. Answer: You don't know. Go to a big PSD->HTML company site and look at their source. It's at least going to be alright. So copy things from their site + portfolio, see how they do things etc