The only ones that will know clearly are Google employees.
The SitePoint forums can help you a lot with on-page optimization, i.e. valid and semantic mark-up, how to reduce page load time etc.
Sadly, most of the posts involving ways to "trick" the Search engines are quite useless if not damaging.
Posts here about off-page optimization even moreso.
Other than an actual Google employee replying to this thread, or someone doing a search for you and posting a link to the Google article they've found, this question is most unlikely to provide anything more that hasn't already been said countless times.