Self-answered questions are ok in general, but:
the Stack Exchange format is not the best for "blog"-type posts. Questions should be questions that have answers. If you can imagine more than one solution to each of your manuals, then they might be appropriate for the site.
Please also note that learning materials are off-topic here, so answers that are in a tutorial format tell me that you might be wandering into an off-topic area.
It sounds like you have a goal of making a "canonical" Q/A, which is great, but consider it in the context of "frequently-asked questions that center around a common element". An answer would be a thorough explanation of some particular scenario, such that anyone else with that scenario could be directed to that Q/A. A canonical Q/A is useful if several people are having the same problem, so the phrasing of your question is critical. Also keep in mind maintenance of the Q/A across software versions, if those updates change features/functionality -- either specify the versions that the Q/A is valid for, or update it as needed.