If you are running Google AdSense on your websites then you are required by Google to have a privacy policy. Due to Google’s interest based targeting you must have some specific language in your privacy policy to let your visitors know whats going on.
Google actually started requiring this early in 2009 but I still see many websites with AdSense ads on them that do not have the proper privacy policy. Not having the proper privacy policy can lead to your AdSense account being terminated so I would urge you to get one up on your site.
Google uses DoubleClick DART cookies which place cookies on your visitors computer in order to better serve ads. So you must let your visitors know this and also link them to the DoubleClick page where they can opt-out of this ad serving on all sites using this advertising by visiting: http://www.doubleclick.com/privacy/dart_adserving.aspx
There is some other stuff that should be in there too but I won’t go into detail about all of it because: a) I am not a lawyer and b) I found a great template you can use for your own sites. It is from Jensense.com and you can view it here
