Here is a short list of tutorials for Cinema 4D, Octane, X-Partilces, Cycles and more. This list will be periodically updated as we discover more online resources.

David Ariew at Arievvisuals.com maintains a great list here: http://arievvisuals.com/resources I will try not to duplicate those found in his list.

3D Fluff YouTube Channel: https://www.youtube.com/channel/UC_8gUT42mj5twt1wCqKF4Mg

Dave Bergin on SkillShare: https://www.skillshare.com/classes/Cinema-4D-Ultimate-Abstract-Art/485905617?via=user-profile

Eyedesyn Cloth Tutorial: https://www.youtube.com/watch?v=Vb5zIpnljjw&feature=youtu.be

All Eyedesyn Tutorials on YouTube: https://www.youtube.com/channel/UCjvsD9ZJRshsmhabFFUH7aA

Greyscale Gorilla YouTube Channel: https://www.youtube.com/channel/UC64Z_7asrekIkc5h2v5tnHw

Insydium (X-Particles and Cycles C4D) YouTube Channel: https://www.youtube.com/channel/UC_wdp70ISEAl0wzI_86bMDw

Motion Designers Community YouTube Channel: https://www.youtube.com/channel/UCBAc7qBoVh0rcDgSJ2thRog

Sean Dove Icing Tutorial: https://www.youtube.com/channel/UC5QgEOuV9CzBCC8XFTV6ZQg

Nikolaus Schatz YouTube Channel: https://www.youtube.com/user/Turboniko68/videos

School of Motion YouTube Channel: https://www.youtube.com/channel/UCAhdxqdrDN3gWJkaUFl9G-Q

Aleskey Voznesenski YouTube Channel: https://www.youtube.com/channel/UClBG-e3Usr3b4oMyxG66imQ