How to Get Started with darktable
No matter your experience with raw photo editing, darktable can be intimidating and has a number of unique features which can be hard to understand at first. So just jumping in and flailing around is not a good strategy for learning. With that in mind, here are my recommendations for getting started properly.
For help and discussion, join the discuss.pixls.us forum, which is the “official” darktable forum and were you'll find the power users and developers. The Play Raw section, in particular, can be a great way to learn.
The Basics
It's important to understand that the workflow and many tools are nothing like in Lightroom or most other raw editors, and trying to fit your old workflow into darktable is almost certainly going to be frustrating. If you have experience color grading video in programs such as Final Cut Pro or DaVinci Resolve, you should find the workflow fairly familiar, though.
The FAQ
Read the new users section before anything else, since that will probably answer some of your questions. https://www.darktable.org/about/faq/
Beginner Tutorials
This is currently the best beginner tutorial: http://youtu.be/ZUc6LOzg_Nk
By watching this tutorial, you'll already understand more than some YouTubers making darktable videos... Do not skip it, no matter your previous experience.
If you're coming from Lightroom or a similar editor, this video will show you the rough equivalents to the tools you already know: https://www.youtube.com/watch?v=6SflKR6JYrk
By the way, there's a shadows and highlights module. Don't use it. It's old and has some serious quality issues.
The Manual
Keep it handy and don't be afraid to read it. It's excellent, and there's a good chance that what you want to know is in there. https://docs.darktable.org/usermanual/development/en/
Next Steps
There are other YouTube channels and tutorials, of course, but they vary greatly in quality, so these are the only ones I can recommend, without reservations, to new users.
Also be aware that starting with version 3.0 and until 3.6, but not really finishing until 4.0, darktable underwent some big changes in the workflow and tools, that mean tutorials made before 3.6 came out (in July 2021) are likely going to contain outdated or even wrong information. Those dealing with specific modules are probably fine, but anything more general should be avoided.
Bruce Williams
Has done a very good job of explaining most features in darktable. His YouTube channel is like an annotated manual. https://youtube.com/@audio2u
Boris Hajdukovic
The darktable wizard. He's the one to watch to take your editing to the next level and learn all the little tricks. https://www.youtube.com/@s7habo
Darktable Landscapes
This is a solid channel for general editing. There are even some videos for users coming from Lightroom. https://www.youtube.com/@DarktableLandscapes
Nicolas Winspeare/A Dabble in Photography
Also solid. Often a bit more technical. https://www.youtube.com/@adabbleinphotography8721