Hello!
You can find the Help Url box when you click the following:
Host -> Modules -> Then choose your Control click edit. On the next window which is named something like "Edit Moduldefinitions" scroll down to the bottom of the page and click on the edit button. In the next window which open up there is the help url box.
I hope I could´ve helped you.
I´ve got a question after experimentin with the help thing. I´ve got selfmade controls which I implemented into DotNetNuke. I want to have each Modulecontainer to have a clickable help image button. If I click the help button it should open up a custom PDF file I created for that specific Modul. Untill now I didn´t manage to get this thing running.
Does somebody know a solution for this? What do I have to do to get the help button for example there where the print image is?