Trying to write an intro to BDSM is quite funny in the modern world, where so much has changed over the last 20 years.
There was no internet when I tripped into it, no web sites, forums, bulletin boards, usenet. Forget about all this ancient houses rubbish, never happened, just a nice affectation for some people to make others think they are better than they really are.
The other problem is trying to put down in words things that you do without thinking, and without missing the important ones. Also adapting it to disability and remembering triggers. It is interesting though.