I’d have to disagree with some of those – I don’t think things like content or even email lists are a definite no-no. There are good, legitimate content writers out there who do great work (for a price, of course), and email spam is illegal but using opt-in newsletter ads I’ve heard can be quite effective. Though it’s true what allfreechips said, don’t try to rush things by throwing money around willy-nilly.
One thing I’d add to the list is agreeing to be a part of those spammy three-way linking deals that always wind up in your spam folder. Google isn’t fooled, and they definitely aren’t designed to benefit you.