New classifieds website needs content and traffic. How can you help?

My website is relatively new and is a niche classifieds website operating in the UK. The site is almost finished and I need to start loading it with content and traffic. I do not know how to do this. It is a classifieds site so it needs accurate and current listings which users will find helpful. It also has a section for users to post their classifieds listings for free and this in turn will drive more visitors to the site. I'm looking for someone who has done this before, and who can help me a) populate the site with good, current and relevant content. and b) drive sustainable traffic to the site which will in-turn help with a).... If you are able to help me with both of the above. Please let me know what your strategy would look like, what you would do, how quickly would I see results, and what your fee would be. Please note that this is a start-up venture and therefore my budget is very tight at this stage. I will provide the website name and URL to interested parties.