What I have found is that there is no one good place to do your advertising. Its best to have several places and ways that you both advertise and market. Since you have joined this forum, I will start with forum marketing.

In forums, you have two opportunities that will work well for advertising. First, is your profile page. You should put your website on your profile page, so that everyone that wants to get to know you a little better will see your website url. You should also fill out your signature line with a small advertisement and your website again. That way, wherever you post in the forum, your advertisement follows you, no matter what you are talking about.

While we are on the subject, you should avoid trying to post discussion after discussion about your opportunity. This is a form of spamming, and not only will these type of discussions be deleted, most people don't respond to them very well.

Another place you can advertise is social networks. You can hook up with people who are like minded, and tell them about your business.

You should also look into free classifieds. You can place several ads about your business on there, and if you post on certain ones, they are scraped by other websites and your ads get automatically placed there as well. This way you can get indexed by google, and you can brand yourself.

Lastly, you can put your website on a few traffic exchanges. Sure, these aren't as good as the other ones, because its not as targeted. But the main point is to get eyeballs on your site, and that way you may get some people interested about your business while you are using the other methods which take a while.

I hope that this helps you some. If you are interested I can give you the names of some of the sites that I use. Just let me know.