This site provides the minimum information needed on an easy and secure way for anonymous internet usage:

1. Install and start VirtualBox (at least version 4).
2. Download two virtual machine (VM) images: Tor gateway and Tor workstation
3. Start VirtualBox and import both VM images (File->Import Appliance)

To start using the internet anonymously you just have to start both VMs Tor gateway and Tor workstation. As soon as they they finished booting, you can use the anonymous internet access through the Tor workstation. If you want to stop using the internet anonymously, just power down both VMs.