Before you drive more traffic to the site, I would recommend that you have valuable content that provides people with the clear information they need or guides them to comfortably make a purchase (or whatever your goal is). If the content is useless or mediocre, you can drive all the traffic in the world to your site, but that won't lead to the results you want. Without having good content first, it's like selling tickets to a concert but not booking the act.
Plus, content development is essential in developing a solid SEO (search engine optimization) strategy. You can learn more about that and see many things you can do yourself here: http://www.seomoz.org/beginners-guide-to-seo
NEVER pay anyone to submit your site to search engines. That practice is obsolete. If someone tries to talk you into doing that, they are either trying to scam you, or they don't know what they're talking about. Also, don't pay for back links. That could get you banned by search engines.
Take a look at the info on that page, and learn more about SEO. If you learn to apply the strategies *effectively* yourself, then you can drive more traffic to your site for free by being relevant to people's searches. It's great to show up on the first page of results when people are actively looking for the information (or product, etc.) you provide.
You could also use social media to drive traffic. I don't have a favorite source that isn't filled with technical and marketing jargon, but if you search "use social media to drive traffic" you'll find useful info.