How can I get targeted traffic?

I am trying to make money through my websites rather than getting a part time job since I want to stay at home with my kids rather than put them in day care. However, I am just not getting enough traffic to my website. Can anyone tell me what I can do to get more traffic to my website? I don’t want just anyone though, I want to have people come that might actually be interested in the products I am selling. I need more targeted web traffic. I know there are methods for increasing this type of traffic, but I don’t know what they are.