How to create a helpfile for a template

I´m working on a template and want to add the helpfile. How do I add this to the template?

How much “help” does it need to give? There is, of course, the “Comment” field on the Properties dialog. From opened template (*.ott) File > Properties... > Description [tab] =

I don’t know how much text can go in there, but there’s one way to find out!

Thanks, I want to be able to use a helpfile with pictures. So your suggestion is not quite what I´m looking for.