here are just a few things:
1. original content is king,
Penguin 2.0 hates spun text, right now it's already a problem but it seems as though Google now has
a special software that checks for the spun articles on your site + for multi-topic spun backlinks and treats you accordingly.
2. social media is super important,
if your content is good, they believe that others want to know about it, so it's important to have facebook, twitter etc accounts....
3. if you build a website strive for the long run,
you simply can't just build thousand of links anymore, you need to have an seo strategy with different kinds of links - no-follow and do-follow, edu, wiki etc... and build them gradually...