I think no one is answering because it is a question most are battling with.
First you need to learn SEO and optimize your site as best you can. The best place to get traffic is the search engines, and they only send it if you have something to offer to surfers. So you need lots of good content – original, because if you copy it becomes duplicate content and the engines will punish you for it.
PPC traffic is still available from some places, it is targeted for the most part, if it is real. With PPC traffic you have a big fraud problem.
PR, in my own opinion, isn’t worth all that much once you are 3 or 4. It doesn’t give you better ranking per se in the engines. Linking is good to do with good websites that match the content of yours. Putting up lots and lots of links at once isn’t all that smart, the engines look like through that. They like to see “natural growth”, so there is no quick shortcut.