All good info above - the best advice is quality content. This means that you actually update your site with real, original content (free hand writing). I see too many templated and cut-paste sites on webmaster forums expecting something better in their traffic.
While backlinks are very important, you need to keep your site fresh. Search engines love this! Also, if you are not original, you are simply competing against other templated sites. Social bookmarking is a great idea for traffic and links but might not rank you higher for
SEO.
Patience is important also! My site is over 10 years old and I still work on my site and content. A very good idea is to look at your competitors to see where and how they rank. Do keyword searches for your subject and fit them (not spam) in your content. I would also recommend (free) Google Analytics. It's just more info for you to look at.
ERIC