Torbutton

You should either user Tor Browser Bundle(TBB)[1] or Tails[2]. Torbutton is part of the TBB.

Torbutton is a 1-click way for users to enable or disable the browser's use of Tor. It adds a panel to the statusbar that says "Tor Enabled" (in green) or "Tor Disabled" (in red). The user may click on the panel to toggle the status. If the user (or some other extension) changes the proxy settings, the change is automatically reflected in the statusbar.

To keep you safe, Torbutton disables many types of active content. You can learn more from the Torbutton FAQ, or read more details in the Torbutton options list.

Some users may prefer a toolbar button instead of a statusbar panel. Torbutton lets you add a toolbar button by right-clicking on the desired toolbar, selecting "Customize...", and then dragging the Torbutton icon onto the toolbar. There is an option in the preferences to hide the statusbar panel (Tools->Extensions, select Torbutton, and click on Preferences).

Torbutton is in the Trisquel repositories as package torbutton-extension and it is recommended you install it from the repositories rather than upstream for the usual reasons.

Security note to users: Want Tor to really work?

...then please don't just install it and go on. You need to change some of your habits, and reconfigure your software! Tor by itself is NOT all you need to maintain your anonymity. Read the full list of warnings.

Attributions: "Tor" and the "Onion Logo" are registered trademarks of The Tor Project, Inc. Content on this site is licensed under a Creative Commons Attribution 3.0 United States License, unless otherwise noted.

[1] https://www.torproject.org/projects/torbrowser.html.en
[2] https://tails.boum.org/