6023 Advertising, Promotion, & SEO

I have a relatively new website, [login to view URL], that allows people to trade items & services (and buy & sell). I need to drive more traffic to the site. It is already indexed on google & yahoo. I would like the site to be in the top 10 when people search for various items or services listed by users, for example, "used law school textbooks." I'm assuming I would need some link campaigns, as well as some SEO (including meta info). I would also like information posted about the site on as many websites and message boards as possible. I already used google & overture. I am open to other suggestions. You must have EXPERIENCE and be able to actually drive traffic to my site/increase search engine rankings with a limited budget right now! There is also the chance that I would maintain you for regular advertising service, if all works well.