1) If you want to invest 0 money,then get a free blog from www.blogger.com and build your first website.
2) If you just want to purchase the domain name and dont want to pay for hosting then get a domain name from www.godaddy.com and get free hosting from some site like www.awardspace.com
3) Write original content on any topic u know the best. like gardening, jewelry, acne, sports, fitness or any thing u know about. Dont copy the content. Write unique content.
4) Apply for google adsene program, www.adsense.com and put ads on your website.
5) Now promote ur website on different forums, and blogs and other websites to get traffic to your website.
6) When people will click on your google ads, you will earn money from google.
7) Be patient and u will win.
8) When ur site will be highly ranked and huge traffic will come to your site, advertisers will contact u to buy the ads space.
But it requires time and patience.