hi-i think you will have to contact employers locally and let them know that you have a site that they can list job openings on. its just a matter of getting the word out i believe. if other people see this thread and respond, im sure there are many other suggestions as well. thanks-and good luck.
Run ad on the frelancer forums.
Try to find places with low prices and high trafic. I believe that target audience for your web site must be everywhare.
Start to SEO/SEM (first time more SEM) for your web site.