While many people have difficulty making any money with Adsense; there are still very many who make a killing with it. If you elect to use Adsense, then read up on their policies because violating the wrong ones will get you removed for life.
One thing you do have to take care about is placing too many ad blocks on any one page.
As far as your overall approach to advertising, you really should do what you think is best; but avoid overdoing it with a bunch of ads. Some people believe that tricking Google is as easy as teaming up with other webmasters and clicking on one another’s AdSense ads so you all make extra profits. Since Google will be able to observe the IP addresses of the computers that keep clicking on each other’s ads, you will soon be caught if you do this.
You are given some degree of flexibility with choice of colors and other options, but you must never alter the code you are given. You guessed it; your account will be banned if you touch the code. You also do not really want your ads to start getting all fouled up, anyway. In the long run, you’ll do much better with Google AdSense if you focus on following the terms of service and setting up your ads and sites so you get the highest possible returns. So, if you’re just starting out with Google AdSense, you know what to keep in mind to make sure that you don’t end up having your account disabled.