Most modern web browsers contain extensive controls that give you the ability to make choices about your privacy. Among other things these controls enable you to block or limit cookies.
Start with these sites to learn more about your browser's privacy controls:
Additionally, Firefox and Chrome have extensive repositories of add-ons that can help enhance your control over your privacy:
In addition newer web browsers allow you to set a privacy preference sometimes known as Do Not Track. More information about these privacy settings may be found at the following sites;
For further information about how you can delete and control the cookies that are stored on your computer please see http://www.allaboutcookies.org/