From the blog "The Salt Mine"

Advertising should be the easiest and probably most ignored part of your site. That makes it no less important, but there are a wide variety of ways you can make it both easier on you and more tolerable to handle. I'll try to sum up how to effectively advertise, how to handle your own advertising boards and some common issues people run into. All while simplifying things as much as possible in order to make it a relatively untouched part of your site in terms of the work you have to do.