I am looking for suggestions on how to implement banner ads utilizing google type ads (or someone else) In order to help pay for our drupal 6 website we need to be able to derive some revenue from banner ads.  I am looking for suggestions on how to implement banner ads utilizing google type ads (or someone else) so that the ads display within a predefined rectangle and if the users clicks on an ad (which takes them to a new tab/page) it gives our company some revenue.
The most common ad network is Adsense. You will have to sign up for an account and then you can install the Adsense module which will manage your ads for you. 

Beware however, this isn't a get rich quick type situation. Making money of Adsense requires a high volume of traffic.