How to promote a website

I had a foolish idea for a website but I’m running with it. I don’t want to post the URL here because frankly it’s a site to make me money and I don’t want to do that off this site.

What I need are suggestions on how to promote the site to a wide audience (without spam)

Get other sites to link to your content, put a link to your site in your signature and post on message boards that relate to your site, advertise (on or offline). Optimize your site for search engines and submit your site to search engines.