1. The official Arduino Starter Kit
Arduino is a great, open-source introduction to microcontrollers. Here are 12 products that can get you started working with Arduino.
Available in the U.S. as the Arduino Starter Kit and outside the U.S. as the Genuino Starter Kit, this box brings with it a 150-page book to walk new hobbyists through the process of working with Arduino. This kit is $99.