DuckDuckGo now offers a new Tor .onion url over HTTPS. This brings DuckDuckGo to the ultimate in privacy and anonymous searching!
The url is: https://3g2upl4pq6kufc4m.onion
If you are new to Tor, I suggest using the Tor Browser Bundle available for Windows, Mac, and Linux. The Tor browser bundle is a stand-alone browser that connects to Tor independant of the rest of your computer.