Recommended · for beginners
SparkFun According to Pete #34: PCB Layout
Why people recommend it
A SparkFun video pointed to as a starting point for PCB design and layout basics, paired with their written Eagle tutorials.
Watch for: Eagle focused; pairs with SparkFun's text guides
In their words
Sparkfun has a great videos on PCB design such as this one.
PyFire on electronics.stackexchange.com, Sept 2019. CC BY-SA.
Watch this from sparkfun to cover many of the basics.
Funkyguy on electronics.stackexchange.com, Jun 2015. CC BY-SA.