There are several ways of monetizing a website. One of them is the google adsense, and if that's not helpful you can try out one of the many other alternatives like bidvertiser, adbrite etc.
Other options are in-text advertising, like the kontera, infolinks, echotopic etc. which link certain keywords in your website to the advertisers sites.
Depending on whether you are owning a company website or just a normal informative site, you can sell private advertisements like banner ads etc.
It all helps out when you first have good amount of traffic to your website. This attracts the advertisers.