Seconding duckduckgo. Also, although not perfect, you can use extensions for your browser which help to limit the tracking of your activity and collection of data about you.
If you use firefox try installing the following combination: NoScript, Ghostery, and AdBlock Plus. They block most tracking activity by default but allow you to whitelist websites/companies that you trust.
It won't help you much against the government (see: https://www.eff.org/nsa-spying) since apparently all major ISPs in the US just blanket forward all data and browsing of US citizens to the NSA (usually through "private companies" to avoid legal issues). You can google or duckduckgo this for more information if you want.
Regardless, it definitely does help against the many private companies that try to track your every online move and mouse click, including google adsense.