One thing I would add is a basic diagram of how things are connected. At least for me, I find things much easier to understand when I have a "picture".
Writing turorials is hard. Getting the appropriate level of detail for the target audience is hard. I tend to go into much more detail than most people want, and often get off into edge cases that aren't helpful when trying to explain at the "first level of approximation" per sindy's sage advice:
I am not very good at that.
However, I have seen a lot of things (not by sindy) that are simplified to the extent of not being useful for understanding at a level needed to troubleshoot.
It may be good to start with a "high level" overview (tell they what you are going to explain), then go into more details (explain), then summarize at the end. (tell them what you explained). I think Ed Harmoush does a very good job of explaining in his practicalnetworking.com articles/videos.