You may have seen "sponsored by Gooooogle" on many websites that you've looked at. This is Google AdSense - a simple way for website owners to display Google Ads on their website and earn money for each advert clicked on. Ads are targetted to the content of the page they are displayed on, so visitors to your page are more likely to want to follow those adverts. You can also use Google Search linked into Adsense on your site, so when a visitor carries out a search, search-related ads are also shown.

Obviously the best way to make money from AdSense is to have a site with lots of content. Free reprint article directories are a fantastic source of fresh content for your website, and simple to use. Just a few articles a week soon builds up into a huge targetted-content website. Alternatively, why not purchase a turnkey article directory website that automatically builds it's own content?

Advantages:

(1) Adverts are targetted to each page so you know the adverts will be related to your content.
(2) You make money per advert clicked on.
(3) Anyone with a website of "reasonable content" can join the AdSense Program.
(4) Google gives you the code and plenty of customisation options (ad sizes and colours), making it really easy to put AdSense on your website.
(5) Free to generate new content - just leave the resource boxes hyperlinked and intact.

Disadvantages:

(1) You can only prevent adverts from specific websites from being displayed - not prevent a category from showing. If you want to eliminate competitors, or have a medical advice site, manually removing each competitor or "miracle cure" website can be a time-consuming and ongoing problem.
(2) Do not get involved in click fraud - once Google has identified you as a perpetrator, you will never be a friend of Google again!

For more information: LittleFish Web Design regularly list an excellent AdSense e-book and turnkey article directories in a variety of niches - keep your eyes peeled!