As you already know, if you have a good website with good traffic there is no way you cannot make money off of it. Almost all of the websites have some sort of ads running on them.
One of the ad provider company is Google Adsense. Signing up for adsense account is easy as 1-2-3. You can sign up for one from one of the links on the right side of this blog.
Of course you still have to follow their TOS in order not to get your account deleted but if you follow simple rules which I previously posted here you should be fine.
So in short, if you have good traffic, and good content, you could easily make couple $100 a month or more from Adsense.
