Simulation Nodes can be daunting. This tutorial series shows how they work from the inside out by creating a particle system from scratch.
The result of this tutorial series is a fully functional asset that can be downloaded from the BlenderDiplom Patreon page: https://www.patreon.com/blenderdiplom/
The Cycles Encyclopedia: https://store.blender.org/product/cycles-encyclopedia/
Point Density Magical Effects: http://www.blenderdiplom.com/en/shop/611-point-density-magical-fx.html
BlenderDiplom Products on the Blender Market: https://www.blendermarket.com/creators/blenderdiplom?ref=83