We are using,mostly, free Software like Blender, Krita, GIMP and so on. So everyone can follow the Workshops.

Linkto
Addons
Complete Tutorials/Series
Quick Tips
Special Worshops/Workflows

You can expand the Videos like all YT-Videos or watch them on YT.

Blender VersionTippVideo 
2.76Mist (Cycles)
2.70Mist (Cycles)
2.78Pipes
How to create some very easy!
2.71Metal Floor
2.77Greebles Displacement
2.79Rendering with CPU AND GPU
togehter
2.79Blender-Render passes as sequences (File Output Node)

Blender Tutorial Series

Tutorial CreatorSeries NameVideo  
BornCG VFX Video Editing
Agenzas Brothers
All Modifier(German)

Special Workshops/Workflows

Tutorial CreatorThemeVideo
Gleb AlexandrovFree Photo Scanning Workflow! (VisualSFM and Meshlab) From Photo to a 3D Mesh
CynicatProReal Lanscape
Displacement
Blender DiplomParticle System
Blender DiplomFire with Smoke Emitter

Addons

TypeDescriptionWebsiteVideo LinkExperience
Blender AddonBlender addon for easy extrusion of various shapes on an uneven surfaceGithubNot tested by me
Blender AddonBlender "Crack It" Addon: Making Old Tree With Rough BarkGITHUBNot tested by me
Blender AddonPush/Pull in Blender like in Sketchup (addon extrude and reshape)GumroadNot tested by me
Blender AddonGrass3d-wolf.comUsing this Addon and it's working fine and easy
Blender AddonCreating Pipes fast and easy.
Videolink ist not the Link to the Author, but you can see, how to handle it.
LinkUsing this Addon and it's working fine and easy
Blender AddonEasy HDRI - Blender add-onCodeofartNot tested by me
Blender PBR ADDON3D-WolfNot tested by me
Blender AddonRe-Face (Rigging)Blendermarket (not free)Not tested by me