Driving traffic to your new web site is one of the most difficult things to do unless you have deep pockets and are willing to spend lots of money paying for paid submission [Adwords] but if you do? what are they going to get? blank advertising pages?
I think before you start on your search engine submission dilemma, it would be wise to get some advertisers to post on your web site... Even if it`s for free until you get people interested on your services. Once you`ve reached a good audience of at least 50 free subscribers, then you can perhaps start charging them 10.00 bucks an ad or so. But at this point in your classified business it would be a waste of money if you Work on climbing up the Search Engine Ladder to come to a blank page.
Another thing you can do is, offer your services to people within the Community.. Perhaps your other route to start generating traffic is by linking to other businesses web sites... for example they post a classified ad on your system, and the more links you build the more relevant the search engines would consider your web site, and the cheaper it would be for you in the long run...
Just something to consider....
Web Developer / Owner / Consultant
When starting your own business the need to "know-how" is greater than money!