Seconded -- ESPECIALLY the "quality guidelines" part which often seems to most developers to be an afterthought, while I treat it as the starting point.
But then I've got that whole "content first!" mantra.
REAL SEO isn't rocket science; unique content of value, marked up semantically, socially promoted with natural organic backlinks from people who are actually interested in what you're putting on the web. That's IT. ALL of it.
Everything else the jerkwads who have the giant set of brass to call themselves "SEO Professionals" that has resulted in people and even companies specializing in SEO to the exclusion of everything else? One giant steaming pile of scam artist manure that does nothing but prey on the ignorant, and is why they all run around like chickens with their heads cut off most always immediately followed by ad-hominem attacks against Matt Cutts every time Google announces an update to how they rank pages.
You do it the REAL way and follow those pesky webmaster guidelines, you're golden. Listen to the halfwit garbage the average SEO "expert" will try to bilk you out of money with? Well... be prepared to have your site suddenly slapped down for abuse.