Step #1: download Kali.
First, get the updated download link here https://www.kali.org/downloads/If you already use a Linux box it's more educational to start using the command line ;-)
$ cd && cd Downloads
$ wget -c http://cdimage.kali.org/kali-2.0/kali-linux-2.0-amd64.iso
Step #2: verify it's genuine and intact.
Copy the sha1 hash from the Kali download page:
$ echo "aaeb89a78f155377282f81a785aa1b38ee5f8ba0 kali-linux-2.0-amd64.iso" > kali-linux-2.0-amd64.iso.sha1sum
$ sha1sum -c kali-linux-2.0-amd64.iso.sha1sum
WARNING: don't trust the torrent download and always check the sha1 hash. My torrent client downloaded the iso without errors, but it was corrupt!
Step #3: build a bootable pendrive.
Find your pendrive device, usually it's /dev/sdb (or /dev/mmcblk0 if you use a SD card instead of an USB pendrive).$ sudo fdisk -l
If it is already mounted, unmount it before overwriting:
$ mount | grep /dev/
$ sudo umount /dev/<your-mounted-pendrive-here>
Copy the downloaded ISO over the pendrive device.
WARNING: make sure you copy over the device (i.e. /dev/sdb), not the partition (i.e. /dev/sdb1).
Yes my dear, it wasn't /dev/sda
If you have pv you can show the progress bar:
$ pv kali-linux-2.0-amd64.iso | sudo dd of=/dev/sdb bs=16M
If you don't have pv (pipe-view), use only dd:
$ sudo dd if=kali-linux-2.0-amd64.iso of=/dev/sdb bs=16M
If you are using Windows or Mac, use your preferred tool or UniversalUSBinstaller to burn the pendrive.
You can follow this tutorial series with this tag: kali-everyday