I know that we're using mediawiki, so I can probably find the syntax reference/demo pages type things.
However.
For convenience it would be
nice to have an obvious and prominent link in the wiki (i.e. on the front page.) That way we can also put in something like "If you find this confusing, just dump what you have in plain text form on a page! That way it'll be there, and others can reformat it as needed to look nice. Original research is a good thing!"
And perhaps: "Just remember - the easiest way to insert images is to add the tag "