Quick setup instructions.

1. Download the image located here https://www.offensive-security.com/kali-linux-arm-images/
2. Extract using 7-zip
3. Use Rufus to DD the image to your MicroSD
4. Pop it in the Pi, boot it up, and login using root:toor for the username:password
5. If you want to install additional tools (you will), you can check them out here https://www.kali.org/news/kali-linux-metapackages/
   1. e.g. apt-get install kali-linux-wireless