Google Adsense is a pay per click program offered by google. In pay per click program, adwords advertisements are placed in a publishers blog/website. If a the blog visitor clicks on any of those advertisement, then the publisher is paid accordingly. The amount paid per click depends on the type of keyword that the advertisement belongs to.
Earning revenue through adsense is not that easy. Only if your blog has a very good traffic, may be then you might earn some revenue. Other than that, its really difficult to earn money through adsense.
When I first read about pay-per-click program, I thought it would be a easy job to earn money through adsense. But after I started using adsense, I realised that its not a joke to earn money through adsense. It took me 2 years to get my first cheque, thourgh adsense. I got 126$, but it was not worth enough.
But I would definitely say Google Adsense is not a scam, its truely a trusted website that pays for sure. If your balance has reached more than 100$ then you would definitely get paid, unless you try to click on your own website.
Google Adsense is very strict with their rules. If they feel that you are doing some kind of fraud, then they would directly disable your account without even verifying with you. They will just send you an email, stating that your account is been disable cause they feel its a risk for their adwords advertisers.
I am discussing on this topic, because yesterday my adsence account was disable. But I agree it was my fault that my account got disabled. If your blog/website has a good traffic then you can try for the pay-per-click program through Google Adsense, you will definitely get paid. In order to create a Google Adsense account, you just have to visit http://www.google.com/adsense and click on sign up.
All The Best For Your Adsense Journey......