There are lots of ways of attracting targeted visitors to your sites. You can write articles that would interest your potential clients & submit them to various article directories. You can create branded videos and submit these to sites like youtube/yahoo video etc. Craigslist is a supremely powerful free classifieds site, many businesses are generating a lot of business here. Those are just 3 small examples - find out how your main competitors are generating traffic & business...and emulate that too.
Apart from the the things mentioned by tuksdrr, you can start actively participating in the forums online which are related to your niche or you can start contributing to Yahoo Answers and try to help people related to your niche. Again there are many other ways like submitting your website to so many bookmarking sites available online and enjoy a lots of targeted traffic coming to your website.
Just search for a forum that corresponds with your niche. Then mingle in the forum and add your website to your signature.
Depends, what type of targeting are you talking about. If it's keyword targeting then you can start ads like Adwords on Google as you can keyword target it, and even target by general cities and areas. If it is age group of people, sex, and religon then I am not sure.
in my opinion, the quickest and easiest way to get most targeted traffic is sign up to the various adware traffic networks. for more information go to mediafire.com or similar sites.
Theres lots of methods you can use to get traffic such as social networking, blog traffic, video traffic, etc