From my experience, money can be earned in following ways : PPC

Selling product and services/PPC Affiliates Selling Products and services: If you are skilled enough and you make products or provide specialized services, you can sell them on internet and make a lot of money. For example, if you are a lawyer or you provide law services of any kind, you can sell them and earn thousands over internet. Affiliates: You can make a regular website and put other company product banners on your webpages. You will be given a particular URL to put on those banners. Visitors when click those banners, they get redirected to the banner website. You get paid either for clicks or if they purchase the product, you get paid a commission. You may signup for affiliation
CPC/PPC: This is HOT topic these days. You can earn a LOT of money from various programs like Google Adsense, Bidvertiser, Clicksor, Adbrite, Chitika, etc. All these companies have been tested and they DO pay. Most of these companies offer two types of services: For advertisers and for publishers. If you want to advertise your product, you can signup for an advertising account with top companies like google, bidvertiser, adbrite, clicksor, etc.
CPC/PPC is the easiest and google adsense is best for CPC. Google pays the most out of all CPC/PPC programs. I started with google adsense in November 2005. I learned a lot of tools through out the process, however, there are several sources on internet where you can get google adsense ready websites. All you have to do is purchase hosting space and upload your adsense ready pages. I continuously made little money until mid of 2006. I got a lot of help from I learned the tips and tricks to organize ads in my webpages to earn maximum revenue. Google also provide advertising of your pages and the cost of advertising starts as low as 1 cent per click. While you use adsense codes on your pages, it is very important to review terms and conditions of Google adsense program. Its a competitive world, sooner you start, sooner you will start earning. I earn anywhere from $1,000 to $1,500 every month through adsense. I'm running 2 websites at the moment which have around 30 pages and planning to work on more websites. If you can make thousands of pages , imagine how much money can you make. Hope this information opens up some doors for you. Happy monetizing your website.