Recommended · for beginners
Tutorial 05 for Arduino: Motors and Transistors
Why people recommend it
Part of Jeremy Blum's Arduino series, driving a DC motor through a transistor; followed by beginners, who often then ask about base resistors and battery choice.
Watch for: a 9 V battery struggles to power motors
In their words
I have essentially taken this video tutorial and migrated it to this setup and I am using the Arduino to turn it on and off using the wire library and bitWrite.
Kenn on electronics.stackexchange.com, Feb 2013. CC BY-SA.
I've been following this tutorial on Arduinos, for the ones that are interested it's this one.
Tobias Heuts on electronics.stackexchange.com, Aug 2018. CC BY-SA.
I feel like the current given from the i/o pin should be enough, especially given tutorials like this:
pwee92 on electronics.stackexchange.com, Jul 2013. CC BY-SA.