In the 21st Century, anonymous browsing and keeping safe is MANDATORY! Below is some information about the Tor Browsing Bundle which comes directly from Tor’s Website. This IS NOT the full explanation of Tor; this merely gets you to the right place.
The Tor software protects you by bouncing your communications around a distributed network of relays run by volunteers all around the world: it prevents somebody watching your Internet connection from learning what sites you visit, it prevents the sites you visit from learning your physical location, and it lets you access sites which are blocked.
The Tor Browser Bundle lets you use Tor on Windows, Mac OS X, or Linux without needing to install any software. It can run off a USB flash drive, comes with a pre-configured web browser to protect your anonymity, and is self-contained.
If you’re not using Firefox you are out of your mind! I use some of their bleeding edge pre builds; however, that is neither here nor there.