Matt Cutts from Google has been asked if Google would favor sites that are built following SEO Best Practice techniques, and, that there must be many technically poor sites that actually have fantastic content which shouldn’t be penalised. His answer:
Just because somebody dots every i and crosses every t and gets all their HTML structure right, doesn’t mean that it’s good content. Even if you do brain-dead stupid things and shoot yourself in the foot, but have good content, we still want to return it…
Get started doing good SEO with this guide (PDF) by Google.