Here's a free Principled BSDF Shader guide to help Blender users, an extract from the free PDF guide and YouTube tutorial below, hope you find it useful :D : r/learnblender
How to Use Blender's new ULTIMATE Shader: Principled — Blender Guru
How to use PBR Textures in Blender | cgbookcase.com
114956 - blender 4.0 : Transmission Roughness is missing in Principled BSDF, preventing some textures from being used correctly in previous versions - blender - Blender Projects
BSDF Principled Hair — Blender Manual
BSDF Principled — Blender Manual
Adding shader effects if material is not controlled by the principled BSDF? - Blender Stack Exchange
Blender 2.8 How to use PBR textures with principled bsdf Cycles/Eevee - YouTube