Social networking is a great way to promote your site. Facebook, Twitter, MySpace, etc.
Article marketing will drive an enormous amount of traffic if you write quality relevant articles. Submit them to sites like ezinearticles.com, goarticles.com, etc. If you do not like writing articles, there are people who will do it for you for only five dollars on sites like fiverr.com.

Create backlinks by commenting on other blogs (quality comments, not spam)
Posting on message boards (conversations and have your link in your signature)
Create a free blogger.com blog, squidoo page, hub page, xomba, etc and link them all back to your web site (it will move you up in the search engines.
Most importantly, build a list! Use a service like Getresponse.com or aweber.com and start a newsletter. That contact list will generate more sales for you thatn any other single method.

Good luck

Fiverr is very cool. I used it often to get tweets out to large amounts of people at a time. Just make sure you look at the feedback and rating of the seller. I have also had great success (sometimes better than Fiverr) with UpHype.com. This one’s is all about “Hype” and is more focussed on marketing efforts to promote your message, business or product? UpHype jobs are called “Hypes”. Hypes range from promoting your message to a user’s 100,000 Twitter followers to writing an article or press release for your blog. http://uphype.com.