I want to start a classifieds site that covers an entire state, every county in the state. My question is how will i get people to post items for sale or anything from the start? If new people come to the site and don't see any ads they are going to leave obviously.

The site will be free to post ads but i do want to make money off of job listings and real estate listings. When can i start to charge for that? Right from the start or when the site gets more popular? If i start out not charging and then charge later on i will lose a lot of visitors im sure, so i don't know what to do. I appreciate your feedback in advance.

I'd recommend finding out your target market first. Decide which state your using, and see how much competition you have, and see what the need for a classifieds is in the state. Then, if it's a state close to you, post some flyers up in local newsagents (places that sell papers and stuff, I don't know if newsagents is a word in American), telling people that it's about. Also, contact people you know who live in that state. Or go to other classifieds and see if you can find your state and inform that person about your classifieds.