When you are first learning how to make your own electronics with the likes of Arduino, the process can be confusing and overwhelming. Arduino forum member Romano d'Ezzelino wanted to make things a little easier, so he designed a simple pinout sheet to track where all the power goes.
The pinout diagrams are easy to read and especially helpful for beginners. You can print them out full-size, so you can set your Arduino Uno, ATMega or ATTiny right on top for a quick reference.
The project was inspired by forum member Graynomad's Arduino Due diagram, so be sure to grab that one as well.